yusnita hamzah | Universiti Malaysia Terengganu (original) (raw)

Papers by yusnita hamzah

Food Research, Jan 11, 2023

Gum Arabic (GA) is the dried exudate obtained from the tree of Acacia senegal and Acacia seyal th... more Gum Arabic (GA) is the dried exudate obtained from the tree of Acacia senegal and Acacia seyal that possess a prebiotic effect on humans. Meanwhile, roselle is a popular juice that is rich in antioxidants. However, as a complex polysaccharide, the addition of GA in roselle juice may affect the antioxidant properties of the final product. Therefore, this study aimed to determine the effect of different types of GA (Acacia senegal or Acacia seyal) addition, at different concentrations (0%, 2%, 4% and 6%) on the antioxidant properties and antioxidant stability of roselle juice during storage. The most accepted formulation of juice for each GA type along with the control sample (0% GA) was analysed for their oxidative stability during five weeks of chill storage (4±1 o C). Results showed that the addition of GA increased or at least maintained the vitamin C and total phenolic content (TPC) in the range of 11.35±1.26-25.18±1.70 mg/100 mL and 21.04±1.55-45.08±4.76 mg GAE/100 mL, respectively. Nevertheless, the addition of more than 2% of GA significantly reduced (p<0.05) about 7% to 25% of total anthocyanin content. Variation of results was shown by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl free radical-scavenging activity (DPPH) assay. For storage study, all juices (0% GA, 4% A. senegal and 2% A. seyal) exhibited fluctuation in trend for all the antioxidant properties except for TPC which remained stable. In conclusion, overall findings showed the addition of GA may increase or at least maintain the antioxidant properties of the juices except for anthocyanin content and antioxidant activity (DPPH assay). Meanwhile, the addition of GA had a variation that resulted in the oxidative stability of juices during storage.

Universiti Malaysia Terengganu Journal of Undergraduate Research, Oct 31, 2021

Kefir is fermented milk obtained by fermenting milk with kefir grains. Chemical composition from ... more Kefir is fermented milk obtained by fermenting milk with kefir grains. Chemical composition from dairy and non-dairy sources may affect the growth and characterisation of lactic acid bacteria (LAB). In this study, different sources of milk (cow milk) and non-dairy milk (soymilk and coconut milk) were used as fermentation media for kefir products. The objectives of the study were to isolate and characterise LAB from Kefir drink using dairy and non-dairy milk. LAB were isolated using different cultural methods such as MRS Agar, MRS with 0.8% CaCO 3 and M17 Agar. The characteristics of LAB isolates were determined using morphological, biochemical tests and API 50 CHL Kit. Sensory evaluation of the sample of kefir drinks was also determined. Results confirmed that the isolates identified were Lactobacillus buchneri, Lactobacillus brevis 1, Leuconostoc mesenteroides, Lactobacillus acidophilus 3 and Lactobacillus plantarum 1. The L. buchneri, L. brevis, Leu. mesenteroides and L. acidophilus are heterofermentative bacteria, whereas, L. plantarum is homofermentative bacteria. Four LAB isolates have the potential to be used as probiotic strains due to their high resistant to pH and bile salt. The sensory score of these products in the range of 5.00 to 8.00 in nine point hedonic scale. Most of the sensory panelists preferred cow milk (p < 0.05) than coconut milk kefir and soy milk kefir in the sensory evaluation in all attributes. Meanwhile, the preference between coconut milk kefir and soy milk kefir was similar (p>0.05) in all attributes. Therefore, this study will provide benefits to probiotic manufacturers to produce alternative probiotic drink using dairy and non-dairy milk.

Food Research, Jun 2, 2020

Malay cherry fruit or locally known as Ceri Terengganu (Lepisanthes alata Leenh.) is a local trop... more Malay cherry fruit or locally known as Ceri Terengganu (Lepisanthes alata Leenh.) is a local tropical exotic fruit and it is native to Malaysia. The Ceri Terengganu tree is widely distributed in the east coast of Peninsular Malaysia particularly in Terengganu, Pahang and Johor and commonly cultivated as an ornamental plant in the villages and gardens. A limited number of studies had been done on the proximate analysis and postharvest quality of Ceri Terengganu fruit, but the studies on the antioxidant and antibacterial activities of Ceri Terengganu fruit extract are still lacking. Hence, this study aimed to determine the antioxidant and antibacterial activity in the peel, flesh and seed extracts of Ceri Terengganu. The Ceri Terengganu was extracted using 60% ethanol and the total phenolic content (TPC), total flavonoid content (TFC), total monomeric anthocyanins, antioxidant and antibacterial activities were measured using standard methods. The results showed that the seed of Ceri Terengganu had the highest amount of TPC, TFC and antioxidant activity, followed by the peel and flesh extracts whilst the peel extract had the highest total monomeric anthocyanins content. Furthermore, all three extracts of Ceri Terengganu showed inhibition against selected pathogens tested. In conclusion, the seed of Ceri Terengganu possessed the greatest potential to be explored as a source of natural antioxidant and antibacterial agent in the food industry, and thus warrant further investigation.

This research was carried out to study the physical and chemical characteristics of pumpkin Javan... more This research was carried out to study the physical and chemical characteristics of pumpkin Javanese noodle gravy prepared in powder form. The finished product is categorized as an instant product as it only needs to be rehydrated with warm water (60°C) before consumption. Five gravy formulations were developed with the incorporation of two types of flour (tapioca and corn flours) as the thickening agent. Physical characteristics including colour and swelling properties of the final products were evaluated. For chemical analysis, ash, moisture, protein, crude fiber, fat and carbohydrate compositions were also determined. For physical analysis, all formulations showed similar colour appearance of the gravy powder including lightness (L), redness (a*) and yellowness (b*). Pertaining swelling properties of the dried gravy, the water absorption index (WAI) values were low (2.0-3.0g/g), while the water solubility index (WSI) were moderate (33.0-50.0%) when evaluated at both hot (85°C) and cold (25°C) water. In termn of chemical compositions, carbohydrate and fat content increased and decreased, respectively with the addition of tapioca and corn flours. The moisture content of the instant gravy increased with the increased of corn flour addition. There were differences in fiber and ash content in all formulations, but no specific trend was observed. Finally, protein content remained the same in all formulations. This current finding provided information of the gravy powder produced. Further analysis on the characteristics of the rehydrated pumpkin Javanese noodle gravy will provide a more complete picture of the finished product.

Food Research, Feb 18, 2020

The citral compound that contributes to the strong-lemony odour of lemongrass has high volatility... more The citral compound that contributes to the strong-lemony odour of lemongrass has high volatility and low physicochemical stability. To overcome the problems, the inclusion complex of the encapsulation technique was applied with rice starch as a coating material to improve the stability and protect against any unfavourable reaction. Therefore, this study was conducted to determine the structural characterization, citral retention and thermal properties of native rice starch, gelatinised rice starch, inclusion complex of rice starch-citral compound, and inclusion complex of rice starch-lemongrass extract. Lemongrass extract and standard citral compound were homogenised into rice starch dispersion at 80 o C for 15 mins and freeze-dried at −50.0±2.0 o C. The formation of the inclusion complex powder was determined using different analyses including morphological structure using the scanning electron microscope, crystallinity structure was determined with X-ray diffractometer, identification and quantification of citral compound using HS-SPME-GC-FID and the thermal properties of inclusion complex analyzed using differential scanning calorimetry. The microstructure of both inclusion complex of rice starch-lemongrass extract and rice starch-citral compound exhibited a laminated multiangular shape with crumble formation together with the characteristics of V-type pattern of crystalline complexes. The low degree of crystallinity of the inclusion complex of rice starch-lemongrass extract obtained high in citral entrapment (29.34±3.13%) with the highest concentration of citral retention (7.33±0.78 ppm). Both inclusion complex of rice starch-citral compound and rice starch-lemongrass extract displayed an endothermic peak at 138 o C, which is attributed to an inclusion complex occurrence with significant difference (p<0.05) of enthalpy of 0.44±0.05 J/g and 1.61±0.70 J/g, respectively. These findings showed that rice starch was effective in complexing with aroma compounds in improving the stability and protecting the citral compound of lemongrass extract from any unwanted changes. This inclusion complex should be regarded as an important strategy in designing a novel model of citral compound of lemongrass for food flavouring application.

Food Research

Tropical biomedicine, 2020

The microbiological quality of thirty ready-to-eat (RTE) keropok lekor (a sausage shape Malaysian... more The microbiological quality of thirty ready-to-eat (RTE) keropok lekor (a sausage shape Malaysian fish product) was evaluated in comparison to microbiological guidelines for ready to eat foods. The two E. coli isolates were subjected to DNA sequencing, identified and tested for their resistance towards fifteen different antibiotics. The survival and growth of the isolated E. coli strains inoculated in keropok lekor at atmospheric air and vacuum packaging were also evaluated. Results revealed that four samples (13.33%) contained Enterobacteriaceae counts that exceeded the recommended allowable counts of 4.0 log10 CFU/g. Unsatisfactory level of coliforms (< 1.7 log10 CFU/g) was also observed in ten of the samples; two of which contained E. coli (2.1 ± 0.17 and 3.7 ± 0.02 log10 CFU/g), suggesting of poor hygiene and sanitation practices. While the 'Possible E10' E. coli strain was observably resistant towards Nalidixic acid (30µg) alone, B10 E. coli isolate was worryingly re...

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Jurnal Intelek

Ice cream is a favorite dessert for many societies around the world. Eating ice can increase the ... more Ice cream is a favorite dessert for many societies around the world. Eating ice can increase the feeling of fun, enjoyment as well as happiness to individuals. As such, not only it is loved by the youngsters, it is also loved by the elders. A good average calorie for an ice cream is approximately 200 kcal/100g. However, adding more sugar into the ice cream for consumption beyond the limit may cause several health diseases such as obesity, diabetes, and even organ failures. In Malaysia, its ice cream market had increased from RM 795.9 million in 2017 to 3.43 per cent in 2018. Putting the increasing trend and health risks into the equation, in order to ensure that ice cream remains enjoyable by people of all age groups and health backgrounds, the creation of a healthy ice cream formula is necessary. This empirical study investigated customer consumption trend on healthy ice cream, assessed customer perception and proposed marketing strategy to promote the consumption of healthy ice cr...

Proceedings of the First International Conference on Science, Technology, Engineering and Industrial Revolution (ICSTEIR 2020)

This article presented a survey data on the lecturers' perception on online teaching during the C... more This article presented a survey data on the lecturers' perception on online teaching during the COVID-19 outbreak. The study adopted a quantitative approach with an open-ended survey questionnaire to establish lecturers' readiness and their emotional presence in adopting 100% online teaching from home. The questionnaire consists of two sections, quantitative and qualitative. As for the quantitative section, the data comprised of demographic characteristics of research respondents and the qualitative section consisted of staff feedback. The data inclusive of 180 academic staff of Universiti Malaysia Terengganu, Malaysia and was analysed using SPSS 22.0. Therefore, these results offer invaluable evidence for university's management as well as policy makers to make further improvements of online teaching and learning as well as lecturers' readiness in online teaching.

Universiti Malaysia Terengganu Journal of Undergraduate Research

Kefir is a fermented milk obtained by fermenting milk with kefir grains. The chemical composition... more Kefir is a fermented milk obtained by fermenting milk with kefir grains. The chemical composition of dairy and non-dairy sources may affect the growth and characterisation of lactic acid bacteria (LAB). In this study, different sources of milk (cow milk) and non-dairy milk (soymilk and coconut milk) were used as the fermentation media for kefir products. The objectives of the study were to isolate and characterise LAB from kefir drink produced from dairy and non-dairy milk. LAB was isolated using different cultural methods, such as MRS Agar, MRS with 0.8% CaCO 3 , and M17 Agar. The characteristics of the LAB isolates were determined using morphological, biochemical tests and the API 50 CHL kit. The physicochemical composition of the samples was determined using titratable acidity and pH level. Sensory evaluation of the kefir drink samples was also carried out. Results confirmed that the isolates were identified as Lactobacillus buchneri, Lactobacillus brevis 1, Leuconostoc mesenteroides, Lactobacillus acidophilus 3 and Lactobacillus plantarum 1. The L. buchneri, L. brevis, Leu. mesenteroides and L. acidophilus are heterofermentative bacteria, whereas L. plantarum is a homofermentative bacterium. Four LAB isolates have the potential to be used as probiotic strains due to their high resistant to low pH and bile salt. The sensory scores of these products range between 5.00 and 8.00 in the 9-point hedonic scale. Most of the sensory panelists preferred cow milk kefir (p < 0.05) compared with coconut milk kefir and soy milk kefir during the sensory evaluation of all attributes. Meanwhile, the preference between coconut milk kefir and soy milk kefir was similar (p>0.05) in all attributes. Therefore, this study will be useful for probiotic manufacturers in the production of alternative probiotic drinks using dairy and non-dairy milk.

The characteristics of breadfruit starch after cross-linked using 2%, 5%, and 10% of a mixture of... more The characteristics of breadfruit starch after cross-linked using 2%, 5%, and 10% of a mixture of sodium trimetaphosphate (STMP)/ sodium tripolyphosphate (STPP) (99/1% w/w) and their feasibility in batter formulation were investigated. The concentrations of 2%, 5%, and 10% of STMP/STPP led to high (85.99%) medium (64.43%) and low (49.59%) cross-linking degree of breadfruit starches, respectively. Swelling power of native and high cross-linked breadfruit starches (CLBS) were significantly higher than that of medium and low CLBS. In addition, enthalpy of gelatinization (ΔH) of high cross-linked CLBS was the lowest (1.81 J/g) among the others. Different degrees of cross-linking did not significantly affect the appearances (size and shape) and crystallinity of breadfruit starches. Batters were prepared by combining wheat flour and native or CLBS (1:1). All batters behaved as shear-thinning fluids and batter with the highest cross-linking degree (CLBS with 2% STMP/ STPP) had the highest ...

Rose cactus (Pereskia bleo) leaves contain a complex polysaccharide called mucilage, which its fu... more Rose cactus (Pereskia bleo) leaves contain a complex polysaccharide called mucilage, which its functionality in foods should be better explored. This study aimed to investigate the effects of different purification mediums on the chemical and functional properties of rose cactus mucilage (RCM). Crude mucilage from leaves of rose cactus was extracted by using 0.14 M NaOH solution at 70°C. Three different purification mediums were employed i.e. isopropanol, saturated barium hydroxide and Fehling solution to obtain mucilage that pure in chemical composition with improved functional properties. Of all mediums, saturated barium hydroxide significantly (p < 0.05) gave the highest recovery yield (52.61%) of RCM, with the best properties especially in terms of crude protein content (26.01%), solubility at 60°C (87.19%), water holding capacity (WHC) (393.88%) and also with emulsifying capacity and emulsion stability (at 1% solution) of 14.11% and 10.44%, respectively. The values were also...

Kasetsart Journal - Natural Science

The effect of additives in Aloe vera (AV) gel coating was investigated on fresh-cut guava stored ... more The effect of additives in Aloe vera (AV) gel coating was investigated on fresh-cut guava stored at 5 °C and 75–80% relative humidity. Eight treatments were employed involving three additives and their combinations. A control sample coated only with AV gel and a comparison sample of uncoated fresh-cut guava were also prepared. The additives used were 1.5% ascorbic acid (AA), 2% calcium chloride (CaCl2), and 0.2% potassium sorbate (PS). Additives helped to extend the shelf life of the coated samples, with PS and AA giving the highest inhibition effects. AV + CaCl2-coated guava showed the lowest weight loss (3.57 ± 0.39%) whilst maintaining sufficient hardness. The coated samples had less change in the color lightness and yellowness compared to the uncoated sample. Five selected coated samples and a fresh uncoated sample were then subjected to sensory acceptance testing. AV + AA + PS-coated guava was the most acceptable sample. Moreover, it gave the highest ascorbic acid content (190....

Food Research

Roselle has a brilliant red colour, high in vitamins and has a unique flavour that makes it suita... more Roselle has a brilliant red colour, high in vitamins and has a unique flavour that makes it suitable for juice production. Meanwhile, Gum Arabic (GA) is the edible dried exudate attained from stem and branch of Acacia senegal that contains high dietary fibre which can serve as prebiotic. Therefore, the application of GA into roselle juice might promote health benefits to consumers. GA is categorised as hydrocolloid and its application might affect important properties and acceptability towards the product. Hence, this study was conducted to investigate the effect of different concentrations of Gum Arabic (GA, Acacia senegal) addition (0%, 2%, 4% and 6%) on physicochemical properties and sensory acceptability of roselle juice. Increasing the GA concentration resulted in increased pH, total soluble solids, viscosity and turbidity values of roselle juice (p<0.05). However, the addition of GA had reduced the total anthocyanin content in roselle juice. For colour analysis, the additio...

International Journal of Food Science and Technology, 2007

A study was carried out to evaluate the effects of three types of flours, namely wheat (W), rice ... more A study was carried out to evaluate the effects of three types of flours, namely wheat (W), rice (R) and sago (S) on the processing parameters of fried battered chicken wing. The parameters were coating pickup, cooked yield and cooking loss. The batter formulation includes 85% of flour and 15% of other ingredients. A mixture design was used to model the processing parameters of the battered fried product with single, binary and ternary combinations of wheat, rice and sago flour. Viscosity measurement of the batter was conducted using Brookfield viscometer. Results showed that, coating pickup and percentage of cooked yield of the product improved when wheat flour was increased in the mixture. Cooking loss of fried battered product increased when sago flour was increased. The higher the viscosity of the batter, the higher the coating pickup and cooked yield, whereas lower viscosity resulted in higher cooking loss of the final product. Incorporation of rice and sago flours resulted in a less viscous and more pourable batter.

International Journal of Food Science & Technology, 2007

The viscoelastic properties of Pereskia bleo mucilage (PBM) and its binary blends with xanthan gu... more The viscoelastic properties of Pereskia bleo mucilage (PBM) and its binary blends with xanthan gum (XG), and locust bean gum (LBG) were studied. Blends of PBM, XG and LBG at six binary blends and native PBM dispersions were prepared at 2% (wt/wt) concentration. There was significant (p < 0.05) increase in storage modulus of PBM when blended with 75% XG at 10 rad/s and with 75% XG and LBG at 100 rad/s. Besides, there was also evident of improvement PBM blends with XG and LBG yet there were significant (p < 0.05) increase in loss modulus of PBM when blended with 75% XG and LBG at 10 rad/s compared native PBM dispersions alone. This study demonstrated improvement of viscoelastic properties of PBM by blending with other commonly known polysaccharides (XG and LBG) which might be attributed with their synergism.

Starches from different types and botanical sources are different in their physical and chemical ... more Starches from different types and botanical sources are different in their physical and chemical properties. In this study, starches from different types (cereal and tuber) had been evaluated for their physical structures, properties and thermal functionalities. Comparison had been made between cassava (tuber,) rice (cereal) and wheat (cereal) starches. Microscopically, a variety of granule sizes and shapes were exhibited by these starches. Among these, rice starch exhibited the smallest particle with the average of 10μm in sizes. The high swelling power of cassava starch was significantly different from the swelling power of rice and wheat starches. The apparent amylose content of starches and the granule size, which were higher in cassava and wheat starches, did not seem to be related with this swelling property. All starches studied exhibited an A-type crystalline pattern. Starches' percent crystallinity was found to have an effect on their gelatinization properties as well a...

Food Research, Jan 11, 2023

Universiti Malaysia Terengganu Journal of Undergraduate Research, Oct 31, 2021

Food Research, Jun 2, 2020

Food Research, Feb 18, 2020

Food Research

Tropical biomedicine, 2020

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Jurnal Intelek

Proceedings of the First International Conference on Science, Technology, Engineering and Industrial Revolution (ICSTEIR 2020)

Universiti Malaysia Terengganu Journal of Undergraduate Research

Kasetsart Journal - Natural Science

Food Research

International Journal of Food Science and Technology, 2007

International Journal of Food Science & Technology, 2007