Food Preservation Research Papers - Academia.edu (original) (raw)

The safety of irradiated pork packed in 25% CO2:75% N2 and stored at abuse temperature (10 or 15°C) was assessed by inoculation studies involving Salmonella typhimurium, Listeria monocytogenes, Escherichia coli, Yersinia enterocolitica... more

The safety of irradiated pork packed in 25% CO2:75% N2 and stored at abuse temperature (10 or 15°C) was assessed by inoculation studies involving Salmonella typhimurium, Listeria monocytogenes, Escherichia coli, Yersinia enterocolitica and Clostridium perfringens. Irradiation to a dose of 1.75 kGy reduced pathogen numbers to below the detection limit of 102 cells g-1. When higher inoculum levels were used (106 cells g-1) irradiation at 1.75 kGy reduced pathogen numbers by 1 –>5 log10 cycles depending on strain. Clostridium perfringens was the most resistant, and Y. enterocolitica the most sensitive of the pathogens studied.In all cases when high numbers (106 to 107g-1) of spoilage and/or pathogenic bacteria were present initially on the pork the meat appeared spoiled, and although irradiation reduced the number of microorganisms, the meat was still unacceptable from a sensory viewpoint after treatment.It was concluded that the microbiological safety of irradiated, modified atmosp...

The scavenging activity against DPPH (1,1-diphenil-2-picrylhydrazyl) radical and the antifungal effect against chloroform, ethyl acetate and 50% methanolic extracts of Verbena officinalis leaves were investigated. The activity of... more

The scavenging activity against DPPH (1,1-diphenil-2-picrylhydrazyl) radical and the antifungal effect against chloroform, ethyl acetate and 50% methanolic extracts of Verbena officinalis leaves were investigated. The activity of different fractions of 50% methanolic extract and some isolated compounds were also investigated. The results suggest that 50% methanolic extract and caffeoyl derivatives could potentially be considered as excellent and readily available sources of natural antifungal and antioxidant compounds.

The effect of osmotic dehydration on the volatile fraction of kiwi fruit was studied, as well as the effect of freezing and frozen storage. Osmotic treatments were carried out in sucrose solutions until the kiwi fruit reached 30°Brix, at... more

The effect of osmotic dehydration on the volatile fraction of kiwi fruit was studied, as well as the effect of freezing and frozen storage. Osmotic treatments were carried out in sucrose solutions until the kiwi fruit reached 30°Brix, at atmospheric pressure (OD) and by applying a vacuum pulse (PVOD), by using 45 and 65°Brix sucrose. Volatile compounds of fresh, dehydrated

ABSTRACT: This study investigated the efficacy of pulsed UV-light for continuous-flow milk treatment for the inactivation of Staphylococcus aureus, a pathogenic microorganism frequently associated with milk safety concerns. Pulsed UV... more

ABSTRACT: This study investigated the efficacy of pulsed UV-light for continuous-flow milk treatment for the inactivation of Staphylococcus aureus, a pathogenic microorganism frequently associated with milk safety concerns. Pulsed UV light is an emerging technology, which can be used for the inactivation of this pathogen in milk in a relatively short time. Pulsed UV light damages the DNA of the bacteria by forming thymine dimers that lead to bacterial death. The effect of sample distance from the quartz window of the UV-light source, number of passes, and flow rate was investigated. A response surface methodology was used for the design and analysis of experiments. Milk was treated at 5-, 8-, or 11-cm distance from a UV-light strobe at 20, 30, or 40 mL/min flow rate and treated up to 3 times by recirculation of milk to assess the effect of the number of passes on inactivation efficiency. Log10 reductions varied from 0.55- to 7.26-log10 CFU/mL. Complete inactivation was obtained in 2 cases and no growth was observed following an enrichment protocol. Predicted results were in agreement with the experimental data. Overall, this work demonstrates that pulsed UV-light has a potential for inactivation of milk pathogens.

A polymerase chain reaction (PCR) was developed for the detection of Clostridium botulinum type A, a cause of human botulism. A two primer set and an oligonucleotide detection probe were used to specifically detect Cl. botulinum type A... more

A polymerase chain reaction (PCR) was developed for the detection of Clostridium botulinum type A, a cause of human botulism. A two primer set and an oligonucleotide detection probe were used to specifically detect Cl. botulinum type A neurotoxin gene (BoNT/A). After 40 cycles of amplification, detection of a 798 bp amplified DNA fragment was carried out by agarose gel electrophoresis and Southern blot hybridization. This assay was able to detect 12.5 fg of purified target DNA or five bacteria per reaction. The sensitivity in artificially contaminated food samples after an 18 h enrichment step ranges from 10 to 10(3) bacteria per g according to the type of food samples. No cross-reactions were observed with the other Cl. botulinum toxinotypes and other bacteria found routinely in food. This PCR method may provide a suitable and rapid alternative to standard techniques for detection of Cl. botulinum type A in food samples.

This study evaluated the effectiveness of grape seed extracts (GSE) on lipid oxidation of corn chips stored for 90 days in comparison to tert-butylhydroxytoluene (BHT). Proximate chemical analysis results showed that corn chips contained... more

This study evaluated the effectiveness of grape seed extracts (GSE) on lipid oxidation of corn chips stored for 90 days in comparison to tert-butylhydroxytoluene (BHT). Proximate chemical analysis results showed that corn chips contained low moisture contents (less than 2%) and also that no significant differences were found in the dry matter values in ash, fat, protein, and fiber. Antioxidant activity

In order to study storage time, sensory properties and acceptability among consumers, regular, free-sugar (sucralose [Sucra] or stevioside [Ste]) and free-sugar/reduced calorie (Sucra or Ste], with whey protein concentrate as fat... more

In order to study storage time, sensory properties and acceptability among consumers, regular, free-sugar (sucralose [Sucra] or stevioside [Ste]) and free-sugar/reduced calorie (Sucra or Ste], with whey protein concentrate as fat replacer) milk chocolates were evaluated over storage (0, 3, 6 and 9 months). Quantitative descriptive analysis showed that sensory properties do not change throughout the studied storage period. These results were confirmed by acceptability data. No significant changes (P ≥ 0.05) were observed on acceptability means for appearance, aroma, flavor, texture and overall liking. These results show that sugar-free and reduced calorie milk chocolates prepared with high-intensity sweeteners, Sucra and Ste, with partial fat replacement with whey protein concentrate had a similar storage time behavior as compared with regular chocolates.

This study was conducted to utilize dragon fruit (DF) peel (100% blended, 50:50 blended and strips, 50:50 blended with fruit bits) and passion fruit (PF) juice (10, 15, 20% w/w) into dragon-passion jam. Sensory qualities (color, aroma,... more

This study was conducted to utilize dragon fruit (DF) peel (100% blended, 50:50 blended and strips, 50:50 blended with fruit bits) and passion fruit (PF) juice (10, 15, 20% w/w) into dragon-passion jam. Sensory qualities (color, aroma, taste, mouthfeel and general acceptability) were evaluated using a 9-point hedonic preference score. A consumer acceptability test was done to validate the acceptance of the optimum formulation. The optimum formulation (50:50 DF blended peel and fruit bits, 15% PF juice) was bounded by an aroma and taste acceptability score of ≥7 by sensory panelist. Parameter estimates from response surface regression (RSREG) analysis indicated that the utilization of DF peel into dragon-passion jam provided a positive response to color acceptability. It was found that 20.22% PF juice was the maximum level required to attain a predicted color acceptability score of 7.12 (moderately liked) and when exceeding 20.22% the predicted color acceptability of the product decreased. Furthermore, the optimum formulation had a potential to compete in the marketplace with a consumer general acceptance score of 8.35 (liked very much) which was higher than the predicted acceptability score.

Mulberry leaf is commonly used for sericulture in almost every part of the world but its potential to be utilized for human consumption is not well recognized. This paper deals with development of mulberry leaf powder and its use with... more

Mulberry leaf is commonly used for sericulture in almost every part of the world but its potential to be utilized for human consumption is not well recognized. This paper deals with development of mulberry leaf powder and its use with wheat flour to develop paratha, the most common food item of breakfast and dinner in the Indian diet. The optimum ratio of the mulberry leaf powder and wheat flour (MLP-WF) mix for preparation of paratha on the basis of sensory quality was found to be 1:4. The protein quality of the MLP-WF mix was estimated by measuring the Protein Efficiency Ratio, and was found to be 1.82 against a casein diet for which a value of 2.44 was observed. The in vivo toxic effect of mix was studied and no adverse effect on the growth of internal organs of rats (heart, liver, kidney and testes) was found. The storage stability of the mix was estimated for a period of 2 months in polyethylene bags at room temperature. A non-significant difference was observed between paratha prepared from fresh and stored mix. This indicated that mix can be stored for a period of 2 months at room temperature without loss of quality.

Fourteen vacuum packed cold smoked salmon products of different origin purchased in Italian retail were analysed at about half shelf-life (HSL) and at the expiry date (ED). On ED, eight on fourteen samples had concentration of total... more

Fourteen vacuum packed cold smoked salmon products of different origin purchased in Italian retail were analysed at about half shelf-life (HSL) and at the expiry date (ED). On ED, eight on fourteen samples had concentration of total volatile basic nitrogen (TVBN) indicating spoilage (values >40 mg N/100 g and up to 71.3 mg N/100 g) and only five samples were not rancid (thiobarbituric acid reactive substances, TBARS <8 nmol/g). Total psychrotrophic count (TPC) at HSL was acceptable (<106 CFU/g) in most samples; at ED, in 13 samples, TPC was very high (range 1.2 × 106– 6.0 × 108 CFU/g) and Lactobacilli were the most representative bacteria. No pathogens were detected. Significant negative differences in declared weight (over 8%) were determined in nine samples. The two months shelf-life attributed to smoked salmon marketed in Italy proved to be, generally, too long and the consumer is at risk to buy a product in early stage of spoilage.