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Papers by Prabir Sarkar

Research paper thumbnail of Preparation of antinutrients-reduced dhokla using response surface process optimisation

Journal of food science and technology, 2018

Dhokla, a popular indigenous savoury dish of India, is prepared by soaking bengalgram dal and ric... more Dhokla, a popular indigenous savoury dish of India, is prepared by soaking bengalgram dal and rice, grinding separately, mixing the batters, and spontaneously fermenting and steaming of mixed batter. Central composite rotatable response surface designs for soaking, fermentation and steaming at five-level combinations were used for optimising preparation of dhokla to achieve reduced contents of antinutrients. Optimum soaking of bengalgram dal (dal-water ratio of 1:5 w/w, pH 7.0, 23 °C, 20 h) and rice (rice-water ratio of 1:5 w/w, pH 5.6, 16 °C, 18 h) resulted in reduced levels of all the antinutrients, except total biogenic amines in rice. Fermentation of dal-rice (3:1 v/v) mixed batter under optimum condition (added NaCl of 8 g/kg, 32 °C, 18 h) further reduced their levels, but total biogenic amines content was enhanced. However, optimum steaming of dal-rice mixed fermented batter for 20 min was effective in reducing all the tested antinutrients. In dhokla, the content of tannins, p...

Research paper thumbnail of Effect of Sugar Level in Milk for Cooking Prechurpi on the Quality of Dudhchurpi

Indian Journal of Dairy Science, 1999

Research paper thumbnail of A survey of ethnomedicinal plants of Darjeeling hills for their antimicrobial and antioxidant activities

The aims of this study were to document ethnomedicinal knowledge of the tribes of Darjeeling hill... more The aims of this study were to document ethnomedicinal knowledge of the tribes of Darjeeling hills and evaluate antimicrobial and antioxidant activities among the sampled plants. The study reports 78 plant species (47 families and 70 genera) from the three hilly subdivisions of Darjeeling district. For antimicrobial evaluation, disc diffusion assay was used against a panel of 11 microorganisms (6 Gram positive bacteria species, 1 Gram negative bacteria species, 2 yeast species and 2 mould species). Antioxidant potential of the plants was investigated by assaying their total phenol content, total flavonoid content, DPPH • , • OH and ABTS •+-scavenging activities, reducing power, metal-chelating activity and anti-lipid peroxidation activity. For statistical analysis, Pearson's Chi Square test was used. Both PRTAU (plants with reports of traditional antimicrobial use) (40.3%) and PNRTAU (plants with no reports of traditional antimicrobial use) were equally active against the microorganisms tested. The χ 2-test confirms that statistically there is a difference in count of PRTAU versus PNRTAU plants in different activity groups, indicating PRTAU plants have higher (P<0.05) probability (71.4% for PRTAU against 35.3% for PNRTAU) of showing lower MIC values than PNRTAU plants. In both the groups, plants displayed good antioxidant activities.

Research paper thumbnail of Optimization of soaking condition of blackgram to minimize flatogenic sugar content in blackgram-based products

LWT - Food Science and Technology, 2015

Abstract Raffinose family oligosaccharides (RFOs), comprising 41.7 g/kg blackgram dal (dry wt bas... more Abstract Raffinose family oligosaccharides (RFOs), comprising 41.7 g/kg blackgram dal (dry wt basis), are important antinutritional factors. In this study, response surface methodology was used to optimize the soaking conditions of blackgram dal in order to reduce these flatogenic sugars. A central composite rotatable design was used to study the effect of four separate soaking parameters. The optimum soaking condition obtained was: bean-water ratio of 1:10, and soaking temperature, time and pH being 16 °C, 21 h and 6.0, respectively, in which the total RFO content predicted in soaked dal was 1.97 g/kg (dry wt basis). The experimentally obtained value was 2.02 g/kg (95.16% reduction over raw dal). Lack of significant difference between the experimental and predicted values validates accuracy of the model. While fermentation of mixed batter prepared by using traditionally soaked dal led to 57.35% decrease in the total RFO content, that prepared by using optimally soaked dal reduced the contents of each of the RFOs below their respective limits of detection (decrease of total RFOs by >93.85%). Steaming of the fermented batter for 15 min had no significant effect on the RFO content.

Research paper thumbnail of Optimization of soybean processing into kinema, a Bacillus-fermented alkaline food, with respect to a minimum level of antinutrients

Journal of applied microbiology, Jan 16, 2015

Optimization of traditional processing of soybeans using response surface methodology (RSM) to ac... more Optimization of traditional processing of soybeans using response surface methodology (RSM) to achieve a minimum level of antinutritional factors (ANFs) in kinema. Central composite rotatable designs were used to optimize the processing stages of kinema preparation. In each stage, the linear or quadratic effects of independent variables were significant in minimizing ANFs levels. The predicted optimum condition for soaking was when the raw beans-water ratio was 1:10, and the soaking temperature, time and pH were 10ºC, 20 h and 8.0, respectively. Here, tannins content (TC), phytic acid content (PAC) and trypsin inhibitor activity (TIA) decreased (P < 0.05). While haemagglutinating activity (HA) level remained unchanged (P < 0.05), total biogenic amines content (TBAC) increased. The optimum condition for cooking was soaked beans-water ratio of 1:5, and cooking pressure and time of 1.10 kg cm(-2) and 20 min, respectively. Here, TC, PAC, TIA and HA decreased (P < 0.05), but TBA...

Research paper thumbnail of NaCl-Added Soybean Fermentation and Post-Fermentation Moisture Modulation: Effects on Safety and Shelf Life of a Traditional, Nonsalted Alkaline Food

Journal of Food Processing and Preservation, 2014

ABSTRACT The present study aimed to evaluate the effect of adding NaCl prior to fermentation and ... more ABSTRACT The present study aimed to evaluate the effect of adding NaCl prior to fermentation and moisture reduction after the fermentation on the safety and shelf life of kinema, a Bacillus-fermented soybean food. The physicochemical parameters of kinema decreased with an increase in the concentration of NaCl up to 4 g/100 g where there was no significant change in cell count of the fermenting microorganism (Bacillus subtilis) and sensory score of the product but eliminated Bacillus cereus. Escherichia coli was reduced by 1 log cycle in the presence of NaCl but eliminated when the water activity (aw) of kinema was reduced to 0.5 after fermentation. Salt had no effect on its shelf-life. Storage stability was determined in terms of its moisture sorption isotherms. Thermodynamic functions decreased with increasing moisture content. The monolayer moisture content ranged from 6.0 to 8.3 g/100 g and the optimum aw for storage of kinema was ≤0.5.Practical ApplicationsAs producers do not adopt safety measures during its preparation, kinema is not always microbiologically safe for consumption. Through the present study it will be possible to eliminate pathogens like B. cereus and E. coli from kinema by the combined effect of salt and aw. The enhanced safety level achieved opens up a future scope for exploring the possibilities of its use as a flavoring or food supplement ingredient. The sorption study revealed the ideal conditions for storage of kinema and can be utilized in the future for designing packaging materials that will ensure better food quality. The combination of salt and aw is applicable to other traditional Bacillus-fermented legume foods, like Thai thua nao, Korean chongkukjang and African dawadawa.

Research paper thumbnail of Prevalence and characterization of Bacillus cereus group from various marketed dairy products in India

Dairy Science & Technology, 2014

Bacillus cereus group, associated with foodborne outbreaks and dairy defects such as sweet curdli... more Bacillus cereus group, associated with foodborne outbreaks and dairy defects such as sweet curdling and bitterness of milk, is an indicator of poor hygiene, and high numbers are unacceptable. In the present study, the prevalence of B. cereus group was investigated in a total of 230 samples belonging to eight different types of dairy products marketed in India. The prevalence of B. cereus group in cheese, ice cream, milk powder, and milk was high (33%-55%), whereas it was low in butter and paneer samples (20% and 4%, respectively). None of the curd and khoa samples were found contaminated. The level of contamination in the various dairy products was up to 10 8 cfu.g −1 or mL −1. An antibiogram of 144 isolates of B. cereus group was obtained using 14 different antibiotics commonly used against foodborne diseases. All the 144 isolates were multidrug (at least five antibiotics) resistant. Ninety-three percent of them exhibited β-hemolysis. Of the 144 isolates, 97%, 96%, and 63% were capable of producing protease, lipase, and amylase, respectively, indicating spoilage potentiality of the isolates. Seventy-one percent of the isolates formed biofilm at 4°C. The principal component analysis allowed classifying different correlated variables into two types of risks (spoilage and food poisoning). Hierarchical cluster analysis classified isolates into four main groups on the basis of the studied characters. The present study will help to better assess the health and spoilage risk associated with B. cereus group in dairy environment and to incorporate adequate preventive measures.

Research paper thumbnail of Moisture sorption characteristics of dudh churpi, a traditional milk product in India

Nahrung/Food, 2002

The sorption isotherms of dudh churpi, a shelf-stable traditional milk product in India, determin... more The sorption isotherms of dudh churpi, a shelf-stable traditional milk product in India, determined at 15, 25, 35 and 45 degrees C, were typical type II sigmoidal according to the BDDT (Brunauer-Deming-Deming-Teller) classification. Nine equations, namely Bradley, Henderson, Iglesias and Chirife, Khun, Mizrahi, GAB (Guggenheim-Anderson-de Boer), modified Mizrahi, Oswin and Caurie were fitted to the sorption data. Caurie&amp;amp;#39;s equation was found to be suited best to predict equilibrium moisture content of dudh churpi. Monolayer value, density of sorbed water, number of monolayers and area of adsorbent decreased with the increase in temperature.

Research paper thumbnail of Oligosaccharide profiles of soybeans during kinema production

Letters in Applied Microbiology, 1997

Oligosaccharide profiles of unfermented and fermented soybeans were determined by a high-performa... more Oligosaccharide profiles of unfermented and fermented soybeans were determined by a high-performance liquid chromatographic method using a Hypersil NH 2 column. In raw soybeans, mean contents of sucrose, raffinose and stachyose on a dry weight basis were 6•3, 1•9 and 4•3%, respectively (ratio of 3•3 : 1 : 2•3). Although soaking and cooking treatments caused a 73-88% reduction in oligosaccharide content, fermentation lowered these levels below the limit of detection (1•0 g kg −1 dry wt), thus eliminating a potential cause of flatulence for consumers.

Research paper thumbnail of Use of Bacillus subtilis isolates from Tua-nao towards nutritional improvement of soybean hull for monogastric feed application

Letters in Applied Microbiology, 2014

Soya bean hull (SBH) is a cheap and high-fibre content feed ingredient that obtained after soya b... more Soya bean hull (SBH) is a cheap and high-fibre content feed ingredient that obtained after soya bean oil extraction. Microbial fermentation was expected to improve SBH qualities before applying to animals, especially monogastric animals. Two bacterial strains, Bacillus subtilis MR10 and TK8 that were isolated from Tua-nao, a traditional fermented soya bean in northern Thailand, were used for fermented soya bean hull (FSBH) production. Both could easily grow at 37°C in SBH as the sole substrate. MR10 produced the highest β-mannanase activity (400 U g(-1) SBH) on day 2, while TK8 produced the highest cellulase activity (14·5 U g(-1) SBH) on day 3. After fermentation, the nutritional quality of SBH was obviously improved by an increase in soluble sugars, soluble proteins, crude protein and crude lipid, and a decrease in the content of raffinose family oligosaccharides. Scavenging activity (%) of SBH against ABTS radical cation was also increased from 14 to 27 and 20% by MR10 and TK8 fermentation, respectively. According to the GRAS property of these both strains and various improvements of nutritional values, the fermented SBH proved to be a potential feed ingredient, especially for the monogastric animals. Normally, soya bean hull has been recognized as only a worthless by-product from soya bean oil production process because of its low utilizable nutrients. Our study introduced an alternative way to utilize this worthless residue using biotechnological knowledge. The nutritional quality of soya bean hull was improved by microbial fermentation. Fermented soya bean hull can be used as a cheap, safe and high-nutrient feed ingredient for livestock production, especially monogastric animals, to promote their growth performances, instead of using antibiotics in some regions of the world.

Research paper thumbnail of Traditional fermented foods and beverages of Darjeeling and Sikkim–a review

Journal of the Science of Food and Agriculture, 1988

The various ethnic groups of the Darjeeling district of West Bengal and Sikkim consume a variety ... more The various ethnic groups of the Darjeeling district of West Bengal and Sikkim consume a variety of fermented foods including kinema (based on soya beans), gundruk (Brassiea campestris leaves), sinki (radish, Raphanus sativus), mesu(bamboo shoots), churpi (milk), shelroti (rice preparation) and jnards (beers). These have not previously been investigated, and their method of preparation and consumption are reported here. The flora of murcha, the starter culture of fnaras. contains mainly Pedioeoecus, yeasts belonging to the get,era Saccharomycopsis, Picbia and Saccharomyces and the moulds Rhizopus and Mucor.

Research paper thumbnail of Response surface optimisation of extraction of antioxidants from strawberry fruit, and lipid peroxidation inhibitory potential of the fruit extract in cooked chicken patties

Journal of the Science of Food and Agriculture, 2011

Strawberries contain high levels of antioxidants and have beneficial effects against oxidative st... more Strawberries contain high levels of antioxidants and have beneficial effects against oxidative stress-mediated diseases, such as cancer. They contain multiple phenolic compounds, which contribute to their biological properties. Hence, a study was carried out to optimise the extraction of antioxidants and evaluate the antioxidant potential of strawberry fruit extract (SE) in cooked chicken patties during refrigerated storage. The activity of SE was compared with that of butylhydroxytoluene (BHT). The effect of solvent type (MeOH and EtOH), concentration (0-70%) of EtOH in the system, temperature (30-60 °C), and time (30-150 min) on DPPH•-scavenging activity of SE was investigated. Response surface methodology was used to estimate the optimum extraction conditions for each parameter. The maximum predicted DPPH• scavenging under the optimised conditions (100% MeOH, 30 °C, 150 min) was 43% at 1 mg SE mL⁻¹. Freshly prepared chicken patties were treated with 5% and 10% SE and 2% BHT, and stored aerobically at 4 °C for 6 days. SE had no influence (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) on any of the sensory attributes of the patties. The values of thiobarbituric acid reactive substances reduced significantly (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) from 2.47 mg in control patties to 0.312 mg and 0.432 mg malonaldehyde kg⁻¹ sample in 5-SE and 10-SE patties, respectively, on the day 6 of storage. The optimised model depicted MeOH at 30 °C with an extended time of 150 min as the optimum settings for extraction of compounds from strawberry that had the scavenging activity. The study shows that the extraction of natural antioxidants from strawberry can be improved by optimising several key extraction parameters. SE also acted as an effective antioxidant and suppressed lipid peroxidation in cooked chicken patties.

Research paper thumbnail of Changes in Soya Bean Lipid Profiles during Kinema Production

Journal of the Science of Food and Agriculture, 1996

The influence of processing on soya bean lipids during kinema production was studied. The crude l... more The influence of processing on soya bean lipids during kinema production was studied. The crude lipid (CL), free fatty acid (FFA) and phytosterol contents of raw beans were 121 g, 6·9 g and 0·8 g kg −1 dry matter, respectively. After soaking and cooking the moisture content of ...

Research paper thumbnail of B-group vitamin and mineral contents of soybeans during kinema production

Journal of the Science of Food and Agriculture, 1998

Concentrations of several B-group vitamins, determined by high-performance liquid chromatography ... more Concentrations of several B-group vitamins, determined by high-performance liquid chromatography (HPLC), and minerals, determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES), in soybeans during different kinema production stages were compared. After ...

Research paper thumbnail of Moisture sorption characteristics of wadi, a legume-based traditional condiment

Journal of Food Science and Technology, 2014

Your article is protected by copyright and all rights are held exclusively by Association of Food... more Your article is protected by copyright and all rights are held exclusively by Association of Food Scientists & Technologists (India). This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

Research paper thumbnail of Response Surface Optimization of Mechanized Drying of Wadi, a Legume-Fermented Food Condiment

Journal of Food Processing and Preservation, 2014

ABSTRACT This work was aimed at optimizing the mechanized drying conditions for wadi using respon... more ABSTRACT This work was aimed at optimizing the mechanized drying conditions for wadi using response surface methodology. Three separate variables, found to influence the quality of wadi, were selected. The effect of these independent variables, viz. relative humidity (RH) (20–65%), drying time (24–120 h) and sample diameter (15–35 mm), on the overall acceptability (OAA) based on its sensory attributes and the aw was studied using a central composite design. Twenty experimental runs in triplicate were conducted to obtain the optimal conditions as 42.5% RH, 72-h time and a sample diameter of 25 mm. Wadi prepared under these conditions was organoleptically acceptable. Although all the three factors had an influence on the OAA, the present study indicates that the drying time and size of wadi had a greater influence. The experimental value of both the responses OAA and aw obtained had no significant difference from the predicted values. Practical ApplicationsWadi is a legume-based condiment popularly consumed in the Indian subcontinent. In spite of its popularity, a large-scale production by mechanizing the manufacturing process is not carried out. The manufacturers rely on the solar energy for drying wadi, which restricts its production only to the winter season when the temperature and humidity are optimum for proper fermentation and drying. In order to remove this climate-dependent constraint, the present work was taken up with an aim to optimize the drying conditions of wadi inside a dehumidifier. The conditions, thus, optimized were found to produce wadi of satisfactory sensory qualities and aw values. The latter is an important factor determining the shelf stability of any food, and aw beyond the critical limit can lead to food spoilage. So, optimized manufacturing conditions will always ensure quality production.

Research paper thumbnail of Antioxidant activities of cereal-legume mixed batters as influenced by process parameters during preparation of dhokla and idli, traditional steamed pancakes

International Journal of Food Sciences and Nutrition, 2011

Dhokla and idli are popular breakfast foods in India. The objective of the present study was to e... more Dhokla and idli are popular breakfast foods in India. The objective of the present study was to evaluate their antioxidative properties during different stages of preparation. The effects of fermentation on the enhancement of antioxidative activities were reflected by a higher total phenol content (TPC) in the fermented batters, which also displayed better antioxidative activities than their unfermented batters and steam-cooked products. Fermentation enhanced&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;2.5-fold TPC and&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;125% reducing activity. The fermented batters were better free-radical scavengers, which increased in a time and dose-dependent manner, than either the unfermented batters or their steamed products. There was significant enhancement of metal-chelating and lipid peroxidation inhibitory activities during fermentation. The TPCs of both dhokla and idli extracts were positively correlated with the respective values of other parameters, suggesting a possible role of phenolics in the extracts as the antioxidant. The data also revealed a strong correlation between any two of these five parameters tested.

Research paper thumbnail of Microbiology of mesu, a traditional fermented bamboo shoot product

International Journal of Food Microbiology, 1996

Research paper thumbnail of Antioxidant activities of soybean as affected by Bacillus-fermentation to kinema

Food Research International, 2008

The antioxidant activities of methanolic extract of kinema, fermented using Bacillus subtilis, an... more The antioxidant activities of methanolic extract of kinema, fermented using Bacillus subtilis, and cooked non-fermented (CNF) soybean were evaluated by four in vitro methods, namely stable DPPH Å-scavenging activity, Fe 3+-reducing power, Fe 2+-chelating activity, and activity in linoleic acid emulsion system. The total phenol content of kinema was 144% higher than that of CNF soybean (3.3 mg g À1 dry weight). At all the tested concentrations (10-50 mg ml À1), kinema extract was found to be a better free radical scavenger, which increased in a time and dose-dependent manner, than the CNF soybean extract. The reducing power of kinema was 147% higher than that of CNF soybean (3.8 mg ascorbic acid equivalents g À1 dry weight). At 10 mg ml À1 , the kinema extract exhibited 64% metal-chelating effect which was much higher than the effect shown by CNF soybean (22%). At 50 mg ml À1 , after 24 h, while kinema exhibited antioxidant activity with 44% inhibition of linoleic acid peroxidation, CNF soybean exhibited 36% inhibition. The inhibition of both of them was found to decline with time and reached 26% after 72 h. The total phenol contents of kinema and CNF soybean were positively correlated (P < 0.01) with the respective values of free radical-scavenging activity (r = 0.96 and 0.82), reducing power (r = 0.94 and 0.82), metal-chelating activity (r = 0.95 and 0.76), and lipid peroxidation inhibitory activity (r = 0.91 and 0.82). Whereas the total phenol content in CNF soybean accounted for 68% of each of free radical-scavenging activity and reducing power, 58% of Fe 2+-chelating activity and 66% of lipid peroxidation inhibitory activity, that in kinema could reflect 83-92% of all the antioxidant parameters studied. The data also revealed a significant correlation (P < 0.01) between any two of these five parameters, indicating while total phenol content as the independent variable, all other parameters as the dependent variables. Thus, kinema may be exploited as a functional food to alleviate oxidative stress.

Research paper thumbnail of Microbiological quality of some retail spices in India

Food Research International, 2003

A total of 154 samples of 27 kinds of spices from retail shops of 20 States of India was investig... more A total of 154 samples of 27 kinds of spices from retail shops of 20 States of India was investigated to determine their microbial status. As per ICMSF specifications, the total aerobic mesophilic bacteria (TAMB) count showed that 51% of the samples were in the unacceptable level (> 10 6 cfu g À1). While moulds were detected in 97% of the samples, yeast was found in only one. Bacillus cereus, Clostridium perfringens, Staphylococcus aureus and members of Enterobacteriaceae occurred in 85, 59, 11 and 85%, respectively of the kinds. Whereas black pepper powder, caraway, garlic and red chilli did not contain B. cereus, this foodborne pathogen was found in all the samples of ajmud, small cardamom and cumin powder. Coliforms and faecal coliforms were found in 33 and 15%, respectively of the kinds. Escherichia coli was detected in only one sample, of garlic. Salmonella and Shigella were found only in 2.6% of the samples. Although they contained less TAMB, the non-packaged spices had a higher load of moulds, B. cereus and Enterobacteriaceae than that of polyethylene-packaged ones.

Research paper thumbnail of Preparation of antinutrients-reduced dhokla using response surface process optimisation

Journal of food science and technology, 2018

Dhokla, a popular indigenous savoury dish of India, is prepared by soaking bengalgram dal and ric... more Dhokla, a popular indigenous savoury dish of India, is prepared by soaking bengalgram dal and rice, grinding separately, mixing the batters, and spontaneously fermenting and steaming of mixed batter. Central composite rotatable response surface designs for soaking, fermentation and steaming at five-level combinations were used for optimising preparation of dhokla to achieve reduced contents of antinutrients. Optimum soaking of bengalgram dal (dal-water ratio of 1:5 w/w, pH 7.0, 23 °C, 20 h) and rice (rice-water ratio of 1:5 w/w, pH 5.6, 16 °C, 18 h) resulted in reduced levels of all the antinutrients, except total biogenic amines in rice. Fermentation of dal-rice (3:1 v/v) mixed batter under optimum condition (added NaCl of 8 g/kg, 32 °C, 18 h) further reduced their levels, but total biogenic amines content was enhanced. However, optimum steaming of dal-rice mixed fermented batter for 20 min was effective in reducing all the tested antinutrients. In dhokla, the content of tannins, p...

Research paper thumbnail of Effect of Sugar Level in Milk for Cooking Prechurpi on the Quality of Dudhchurpi

Indian Journal of Dairy Science, 1999

Research paper thumbnail of A survey of ethnomedicinal plants of Darjeeling hills for their antimicrobial and antioxidant activities

The aims of this study were to document ethnomedicinal knowledge of the tribes of Darjeeling hill... more The aims of this study were to document ethnomedicinal knowledge of the tribes of Darjeeling hills and evaluate antimicrobial and antioxidant activities among the sampled plants. The study reports 78 plant species (47 families and 70 genera) from the three hilly subdivisions of Darjeeling district. For antimicrobial evaluation, disc diffusion assay was used against a panel of 11 microorganisms (6 Gram positive bacteria species, 1 Gram negative bacteria species, 2 yeast species and 2 mould species). Antioxidant potential of the plants was investigated by assaying their total phenol content, total flavonoid content, DPPH • , • OH and ABTS •+-scavenging activities, reducing power, metal-chelating activity and anti-lipid peroxidation activity. For statistical analysis, Pearson's Chi Square test was used. Both PRTAU (plants with reports of traditional antimicrobial use) (40.3%) and PNRTAU (plants with no reports of traditional antimicrobial use) were equally active against the microorganisms tested. The χ 2-test confirms that statistically there is a difference in count of PRTAU versus PNRTAU plants in different activity groups, indicating PRTAU plants have higher (P<0.05) probability (71.4% for PRTAU against 35.3% for PNRTAU) of showing lower MIC values than PNRTAU plants. In both the groups, plants displayed good antioxidant activities.

Research paper thumbnail of Optimization of soaking condition of blackgram to minimize flatogenic sugar content in blackgram-based products

LWT - Food Science and Technology, 2015

Abstract Raffinose family oligosaccharides (RFOs), comprising 41.7 g/kg blackgram dal (dry wt bas... more Abstract Raffinose family oligosaccharides (RFOs), comprising 41.7 g/kg blackgram dal (dry wt basis), are important antinutritional factors. In this study, response surface methodology was used to optimize the soaking conditions of blackgram dal in order to reduce these flatogenic sugars. A central composite rotatable design was used to study the effect of four separate soaking parameters. The optimum soaking condition obtained was: bean-water ratio of 1:10, and soaking temperature, time and pH being 16 °C, 21 h and 6.0, respectively, in which the total RFO content predicted in soaked dal was 1.97 g/kg (dry wt basis). The experimentally obtained value was 2.02 g/kg (95.16% reduction over raw dal). Lack of significant difference between the experimental and predicted values validates accuracy of the model. While fermentation of mixed batter prepared by using traditionally soaked dal led to 57.35% decrease in the total RFO content, that prepared by using optimally soaked dal reduced the contents of each of the RFOs below their respective limits of detection (decrease of total RFOs by >93.85%). Steaming of the fermented batter for 15 min had no significant effect on the RFO content.

Research paper thumbnail of Optimization of soybean processing into kinema, a Bacillus-fermented alkaline food, with respect to a minimum level of antinutrients

Journal of applied microbiology, Jan 16, 2015

Optimization of traditional processing of soybeans using response surface methodology (RSM) to ac... more Optimization of traditional processing of soybeans using response surface methodology (RSM) to achieve a minimum level of antinutritional factors (ANFs) in kinema. Central composite rotatable designs were used to optimize the processing stages of kinema preparation. In each stage, the linear or quadratic effects of independent variables were significant in minimizing ANFs levels. The predicted optimum condition for soaking was when the raw beans-water ratio was 1:10, and the soaking temperature, time and pH were 10ºC, 20 h and 8.0, respectively. Here, tannins content (TC), phytic acid content (PAC) and trypsin inhibitor activity (TIA) decreased (P < 0.05). While haemagglutinating activity (HA) level remained unchanged (P < 0.05), total biogenic amines content (TBAC) increased. The optimum condition for cooking was soaked beans-water ratio of 1:5, and cooking pressure and time of 1.10 kg cm(-2) and 20 min, respectively. Here, TC, PAC, TIA and HA decreased (P < 0.05), but TBA...

Research paper thumbnail of NaCl-Added Soybean Fermentation and Post-Fermentation Moisture Modulation: Effects on Safety and Shelf Life of a Traditional, Nonsalted Alkaline Food

Journal of Food Processing and Preservation, 2014

ABSTRACT The present study aimed to evaluate the effect of adding NaCl prior to fermentation and ... more ABSTRACT The present study aimed to evaluate the effect of adding NaCl prior to fermentation and moisture reduction after the fermentation on the safety and shelf life of kinema, a Bacillus-fermented soybean food. The physicochemical parameters of kinema decreased with an increase in the concentration of NaCl up to 4 g/100 g where there was no significant change in cell count of the fermenting microorganism (Bacillus subtilis) and sensory score of the product but eliminated Bacillus cereus. Escherichia coli was reduced by 1 log cycle in the presence of NaCl but eliminated when the water activity (aw) of kinema was reduced to 0.5 after fermentation. Salt had no effect on its shelf-life. Storage stability was determined in terms of its moisture sorption isotherms. Thermodynamic functions decreased with increasing moisture content. The monolayer moisture content ranged from 6.0 to 8.3 g/100 g and the optimum aw for storage of kinema was ≤0.5.Practical ApplicationsAs producers do not adopt safety measures during its preparation, kinema is not always microbiologically safe for consumption. Through the present study it will be possible to eliminate pathogens like B. cereus and E. coli from kinema by the combined effect of salt and aw. The enhanced safety level achieved opens up a future scope for exploring the possibilities of its use as a flavoring or food supplement ingredient. The sorption study revealed the ideal conditions for storage of kinema and can be utilized in the future for designing packaging materials that will ensure better food quality. The combination of salt and aw is applicable to other traditional Bacillus-fermented legume foods, like Thai thua nao, Korean chongkukjang and African dawadawa.

Research paper thumbnail of Prevalence and characterization of Bacillus cereus group from various marketed dairy products in India

Dairy Science & Technology, 2014

Bacillus cereus group, associated with foodborne outbreaks and dairy defects such as sweet curdli... more Bacillus cereus group, associated with foodborne outbreaks and dairy defects such as sweet curdling and bitterness of milk, is an indicator of poor hygiene, and high numbers are unacceptable. In the present study, the prevalence of B. cereus group was investigated in a total of 230 samples belonging to eight different types of dairy products marketed in India. The prevalence of B. cereus group in cheese, ice cream, milk powder, and milk was high (33%-55%), whereas it was low in butter and paneer samples (20% and 4%, respectively). None of the curd and khoa samples were found contaminated. The level of contamination in the various dairy products was up to 10 8 cfu.g −1 or mL −1. An antibiogram of 144 isolates of B. cereus group was obtained using 14 different antibiotics commonly used against foodborne diseases. All the 144 isolates were multidrug (at least five antibiotics) resistant. Ninety-three percent of them exhibited β-hemolysis. Of the 144 isolates, 97%, 96%, and 63% were capable of producing protease, lipase, and amylase, respectively, indicating spoilage potentiality of the isolates. Seventy-one percent of the isolates formed biofilm at 4°C. The principal component analysis allowed classifying different correlated variables into two types of risks (spoilage and food poisoning). Hierarchical cluster analysis classified isolates into four main groups on the basis of the studied characters. The present study will help to better assess the health and spoilage risk associated with B. cereus group in dairy environment and to incorporate adequate preventive measures.

Research paper thumbnail of Moisture sorption characteristics of dudh churpi, a traditional milk product in India

Nahrung/Food, 2002

The sorption isotherms of dudh churpi, a shelf-stable traditional milk product in India, determin... more The sorption isotherms of dudh churpi, a shelf-stable traditional milk product in India, determined at 15, 25, 35 and 45 degrees C, were typical type II sigmoidal according to the BDDT (Brunauer-Deming-Deming-Teller) classification. Nine equations, namely Bradley, Henderson, Iglesias and Chirife, Khun, Mizrahi, GAB (Guggenheim-Anderson-de Boer), modified Mizrahi, Oswin and Caurie were fitted to the sorption data. Caurie&amp;amp;#39;s equation was found to be suited best to predict equilibrium moisture content of dudh churpi. Monolayer value, density of sorbed water, number of monolayers and area of adsorbent decreased with the increase in temperature.

Research paper thumbnail of Oligosaccharide profiles of soybeans during kinema production

Letters in Applied Microbiology, 1997

Oligosaccharide profiles of unfermented and fermented soybeans were determined by a high-performa... more Oligosaccharide profiles of unfermented and fermented soybeans were determined by a high-performance liquid chromatographic method using a Hypersil NH 2 column. In raw soybeans, mean contents of sucrose, raffinose and stachyose on a dry weight basis were 6•3, 1•9 and 4•3%, respectively (ratio of 3•3 : 1 : 2•3). Although soaking and cooking treatments caused a 73-88% reduction in oligosaccharide content, fermentation lowered these levels below the limit of detection (1•0 g kg −1 dry wt), thus eliminating a potential cause of flatulence for consumers.

Research paper thumbnail of Use of Bacillus subtilis isolates from Tua-nao towards nutritional improvement of soybean hull for monogastric feed application

Letters in Applied Microbiology, 2014

Soya bean hull (SBH) is a cheap and high-fibre content feed ingredient that obtained after soya b... more Soya bean hull (SBH) is a cheap and high-fibre content feed ingredient that obtained after soya bean oil extraction. Microbial fermentation was expected to improve SBH qualities before applying to animals, especially monogastric animals. Two bacterial strains, Bacillus subtilis MR10 and TK8 that were isolated from Tua-nao, a traditional fermented soya bean in northern Thailand, were used for fermented soya bean hull (FSBH) production. Both could easily grow at 37°C in SBH as the sole substrate. MR10 produced the highest β-mannanase activity (400 U g(-1) SBH) on day 2, while TK8 produced the highest cellulase activity (14·5 U g(-1) SBH) on day 3. After fermentation, the nutritional quality of SBH was obviously improved by an increase in soluble sugars, soluble proteins, crude protein and crude lipid, and a decrease in the content of raffinose family oligosaccharides. Scavenging activity (%) of SBH against ABTS radical cation was also increased from 14 to 27 and 20% by MR10 and TK8 fermentation, respectively. According to the GRAS property of these both strains and various improvements of nutritional values, the fermented SBH proved to be a potential feed ingredient, especially for the monogastric animals. Normally, soya bean hull has been recognized as only a worthless by-product from soya bean oil production process because of its low utilizable nutrients. Our study introduced an alternative way to utilize this worthless residue using biotechnological knowledge. The nutritional quality of soya bean hull was improved by microbial fermentation. Fermented soya bean hull can be used as a cheap, safe and high-nutrient feed ingredient for livestock production, especially monogastric animals, to promote their growth performances, instead of using antibiotics in some regions of the world.

Research paper thumbnail of Traditional fermented foods and beverages of Darjeeling and Sikkim–a review

Journal of the Science of Food and Agriculture, 1988

The various ethnic groups of the Darjeeling district of West Bengal and Sikkim consume a variety ... more The various ethnic groups of the Darjeeling district of West Bengal and Sikkim consume a variety of fermented foods including kinema (based on soya beans), gundruk (Brassiea campestris leaves), sinki (radish, Raphanus sativus), mesu(bamboo shoots), churpi (milk), shelroti (rice preparation) and jnards (beers). These have not previously been investigated, and their method of preparation and consumption are reported here. The flora of murcha, the starter culture of fnaras. contains mainly Pedioeoecus, yeasts belonging to the get,era Saccharomycopsis, Picbia and Saccharomyces and the moulds Rhizopus and Mucor.

Research paper thumbnail of Response surface optimisation of extraction of antioxidants from strawberry fruit, and lipid peroxidation inhibitory potential of the fruit extract in cooked chicken patties

Journal of the Science of Food and Agriculture, 2011

Strawberries contain high levels of antioxidants and have beneficial effects against oxidative st... more Strawberries contain high levels of antioxidants and have beneficial effects against oxidative stress-mediated diseases, such as cancer. They contain multiple phenolic compounds, which contribute to their biological properties. Hence, a study was carried out to optimise the extraction of antioxidants and evaluate the antioxidant potential of strawberry fruit extract (SE) in cooked chicken patties during refrigerated storage. The activity of SE was compared with that of butylhydroxytoluene (BHT). The effect of solvent type (MeOH and EtOH), concentration (0-70%) of EtOH in the system, temperature (30-60 °C), and time (30-150 min) on DPPH•-scavenging activity of SE was investigated. Response surface methodology was used to estimate the optimum extraction conditions for each parameter. The maximum predicted DPPH• scavenging under the optimised conditions (100% MeOH, 30 °C, 150 min) was 43% at 1 mg SE mL⁻¹. Freshly prepared chicken patties were treated with 5% and 10% SE and 2% BHT, and stored aerobically at 4 °C for 6 days. SE had no influence (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) on any of the sensory attributes of the patties. The values of thiobarbituric acid reactive substances reduced significantly (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) from 2.47 mg in control patties to 0.312 mg and 0.432 mg malonaldehyde kg⁻¹ sample in 5-SE and 10-SE patties, respectively, on the day 6 of storage. The optimised model depicted MeOH at 30 °C with an extended time of 150 min as the optimum settings for extraction of compounds from strawberry that had the scavenging activity. The study shows that the extraction of natural antioxidants from strawberry can be improved by optimising several key extraction parameters. SE also acted as an effective antioxidant and suppressed lipid peroxidation in cooked chicken patties.

Research paper thumbnail of Changes in Soya Bean Lipid Profiles during Kinema Production

Journal of the Science of Food and Agriculture, 1996

The influence of processing on soya bean lipids during kinema production was studied. The crude l... more The influence of processing on soya bean lipids during kinema production was studied. The crude lipid (CL), free fatty acid (FFA) and phytosterol contents of raw beans were 121 g, 6·9 g and 0·8 g kg −1 dry matter, respectively. After soaking and cooking the moisture content of ...

Research paper thumbnail of B-group vitamin and mineral contents of soybeans during kinema production

Journal of the Science of Food and Agriculture, 1998

Concentrations of several B-group vitamins, determined by high-performance liquid chromatography ... more Concentrations of several B-group vitamins, determined by high-performance liquid chromatography (HPLC), and minerals, determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES), in soybeans during different kinema production stages were compared. After ...

Research paper thumbnail of Moisture sorption characteristics of wadi, a legume-based traditional condiment

Journal of Food Science and Technology, 2014

Your article is protected by copyright and all rights are held exclusively by Association of Food... more Your article is protected by copyright and all rights are held exclusively by Association of Food Scientists & Technologists (India). This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

Research paper thumbnail of Response Surface Optimization of Mechanized Drying of Wadi, a Legume-Fermented Food Condiment

Journal of Food Processing and Preservation, 2014

ABSTRACT This work was aimed at optimizing the mechanized drying conditions for wadi using respon... more ABSTRACT This work was aimed at optimizing the mechanized drying conditions for wadi using response surface methodology. Three separate variables, found to influence the quality of wadi, were selected. The effect of these independent variables, viz. relative humidity (RH) (20–65%), drying time (24–120 h) and sample diameter (15–35 mm), on the overall acceptability (OAA) based on its sensory attributes and the aw was studied using a central composite design. Twenty experimental runs in triplicate were conducted to obtain the optimal conditions as 42.5% RH, 72-h time and a sample diameter of 25 mm. Wadi prepared under these conditions was organoleptically acceptable. Although all the three factors had an influence on the OAA, the present study indicates that the drying time and size of wadi had a greater influence. The experimental value of both the responses OAA and aw obtained had no significant difference from the predicted values. Practical ApplicationsWadi is a legume-based condiment popularly consumed in the Indian subcontinent. In spite of its popularity, a large-scale production by mechanizing the manufacturing process is not carried out. The manufacturers rely on the solar energy for drying wadi, which restricts its production only to the winter season when the temperature and humidity are optimum for proper fermentation and drying. In order to remove this climate-dependent constraint, the present work was taken up with an aim to optimize the drying conditions of wadi inside a dehumidifier. The conditions, thus, optimized were found to produce wadi of satisfactory sensory qualities and aw values. The latter is an important factor determining the shelf stability of any food, and aw beyond the critical limit can lead to food spoilage. So, optimized manufacturing conditions will always ensure quality production.

Research paper thumbnail of Antioxidant activities of cereal-legume mixed batters as influenced by process parameters during preparation of dhokla and idli, traditional steamed pancakes

International Journal of Food Sciences and Nutrition, 2011

Dhokla and idli are popular breakfast foods in India. The objective of the present study was to e... more Dhokla and idli are popular breakfast foods in India. The objective of the present study was to evaluate their antioxidative properties during different stages of preparation. The effects of fermentation on the enhancement of antioxidative activities were reflected by a higher total phenol content (TPC) in the fermented batters, which also displayed better antioxidative activities than their unfermented batters and steam-cooked products. Fermentation enhanced&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;2.5-fold TPC and&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;125% reducing activity. The fermented batters were better free-radical scavengers, which increased in a time and dose-dependent manner, than either the unfermented batters or their steamed products. There was significant enhancement of metal-chelating and lipid peroxidation inhibitory activities during fermentation. The TPCs of both dhokla and idli extracts were positively correlated with the respective values of other parameters, suggesting a possible role of phenolics in the extracts as the antioxidant. The data also revealed a strong correlation between any two of these five parameters tested.

Research paper thumbnail of Microbiology of mesu, a traditional fermented bamboo shoot product

International Journal of Food Microbiology, 1996

Research paper thumbnail of Antioxidant activities of soybean as affected by Bacillus-fermentation to kinema

Food Research International, 2008

The antioxidant activities of methanolic extract of kinema, fermented using Bacillus subtilis, an... more The antioxidant activities of methanolic extract of kinema, fermented using Bacillus subtilis, and cooked non-fermented (CNF) soybean were evaluated by four in vitro methods, namely stable DPPH Å-scavenging activity, Fe 3+-reducing power, Fe 2+-chelating activity, and activity in linoleic acid emulsion system. The total phenol content of kinema was 144% higher than that of CNF soybean (3.3 mg g À1 dry weight). At all the tested concentrations (10-50 mg ml À1), kinema extract was found to be a better free radical scavenger, which increased in a time and dose-dependent manner, than the CNF soybean extract. The reducing power of kinema was 147% higher than that of CNF soybean (3.8 mg ascorbic acid equivalents g À1 dry weight). At 10 mg ml À1 , the kinema extract exhibited 64% metal-chelating effect which was much higher than the effect shown by CNF soybean (22%). At 50 mg ml À1 , after 24 h, while kinema exhibited antioxidant activity with 44% inhibition of linoleic acid peroxidation, CNF soybean exhibited 36% inhibition. The inhibition of both of them was found to decline with time and reached 26% after 72 h. The total phenol contents of kinema and CNF soybean were positively correlated (P < 0.01) with the respective values of free radical-scavenging activity (r = 0.96 and 0.82), reducing power (r = 0.94 and 0.82), metal-chelating activity (r = 0.95 and 0.76), and lipid peroxidation inhibitory activity (r = 0.91 and 0.82). Whereas the total phenol content in CNF soybean accounted for 68% of each of free radical-scavenging activity and reducing power, 58% of Fe 2+-chelating activity and 66% of lipid peroxidation inhibitory activity, that in kinema could reflect 83-92% of all the antioxidant parameters studied. The data also revealed a significant correlation (P < 0.01) between any two of these five parameters, indicating while total phenol content as the independent variable, all other parameters as the dependent variables. Thus, kinema may be exploited as a functional food to alleviate oxidative stress.

Research paper thumbnail of Microbiological quality of some retail spices in India

Food Research International, 2003

A total of 154 samples of 27 kinds of spices from retail shops of 20 States of India was investig... more A total of 154 samples of 27 kinds of spices from retail shops of 20 States of India was investigated to determine their microbial status. As per ICMSF specifications, the total aerobic mesophilic bacteria (TAMB) count showed that 51% of the samples were in the unacceptable level (> 10 6 cfu g À1). While moulds were detected in 97% of the samples, yeast was found in only one. Bacillus cereus, Clostridium perfringens, Staphylococcus aureus and members of Enterobacteriaceae occurred in 85, 59, 11 and 85%, respectively of the kinds. Whereas black pepper powder, caraway, garlic and red chilli did not contain B. cereus, this foodborne pathogen was found in all the samples of ajmud, small cardamom and cumin powder. Coliforms and faecal coliforms were found in 33 and 15%, respectively of the kinds. Escherichia coli was detected in only one sample, of garlic. Salmonella and Shigella were found only in 2.6% of the samples. Although they contained less TAMB, the non-packaged spices had a higher load of moulds, B. cereus and Enterobacteriaceae than that of polyethylene-packaged ones.