Nutrition and Food Technology
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- ItemMETABOLIC ATTENUATION OF LACTICASEIBACILLUS CASEI ATCC 393 USING AN EMULSION MICROENCAPSULATION STRATEGY(2022-07-28) HaneenAlrjoobBackground: The attenuation of probiotic bacteria by microencapsulation can be considered as a physical approach to modulate the metabolic activities of the probiotic bacteria when inserted into the food matrix. The aim: of this work is to study the attenuation effect of microencapsulation on Lacticaseibacilluscasei ATCC 393 fermentative metabolism. Then, the attenuating system developed was used to probioticate a food matrix, an orange juice, to test the efficacy of microencapsulation to avoid physico-chemical changes during the storage of the beverage. Methodology: Two probiotic juices were formulated: LC_OJ added of the probiotic in free form and MC_OJ added of the probiotic as microcapsules of 0.8% sodium alginate coated with chitosan. Microbiological and physiochemical tests were carried out for the two juices during storage for 15 days at 4 °C and 15 °C. Results: pH concluded that microencapsulation had no effect on pH when the juice is refrigerated. However the orange juice MC_OJ sample presented lower Titratable Acidity (TA) than LC_OJ for both storage temperatures, meaning that the microencapsulation lowered the TA. In this study, probiotication showed no effects on color change when the orange juice regardless the form of addition. The same is for the ascorbic acid content compared with the free cells form, due to the loss of the vitamin C content during samples preparations and storage. The concluded results for LC_OJ and MC_OJ, demonstrated that microencapsulation of L. casei ATCC 393 didn’t have an attenuation effect. Both LC_OJ and MC_OJ presented high viable counts. Conclusion: when the probiotic L. casei ATCC 393 is added to orange juice there is no need of attenuation. Moreover, orange juice represent a suitable matrix for the probiotication maintaining constant chemical and physical parameters over time and simultaneously ensuring the survival of the probiotic. Keywords: Attenuation, L.casei ATCC 393, Orange Juice, Viable counts, pH
- ItemDEVELOPMENT AND VALIDATION OF FFQ SCREENER SOFTWARE FOR SODIUM INTAKE AMONG PALESTINIAN POPULATION(An - Najah National University, 2023-07-17) Razan Arafat Mohammad AwwadBackground: A high intake of sodium leads to cardiovascular, renal, and immune system effects. It also increases mortality from cardiovascular disease. Traditional sodium evaluation methods such as food frequency questionnaires (FFQ), 24-hour recall, and 24-hour records are inefficient and prone to error. Smartphone applications and software enhance the efficiency and accuracy of dietary assessment. The study aims to design and test a software-based FFQ screener to evaluate Palestinian sodium intake. Also, the relationship between dietary sodium intake, practices, and the FFQ screener, 3-day food recall, and 24-hour urine sodium levels was evaluated. Methodology: The study consists of four phases. In Phase 1, Palestinian foods were classified and subclassified by method of consumption, sodium concentration, and food group. The Palestinian food culture determined serving size and frequency, whereas a database of food composition evaluated sodium levels. Three databases of food composition were used to validate the values. In Phase 2, four nutrition experts and three related researchers assessed the content validity of the FFQ screener. The screener was revised in response to their recommendations. In Phase 3, a pilot study assessed the reliability of test-retests. In Phase 4, the criteria validity of the screener was evaluated by comparing FFQ sodium intake data to 24-hour urine sodium test (Gold standard 1) and 3-day recall (Gold standard 2) results. SPSS was used to compare and evaluate the results. Results: The FFQ sodium screener included 41 food items organized into nine categories, with photo-based estimations of portion size and frequency of consumption for each. The reliability test revealed a Pearson correlation coefficient of 0.70 (p0.01) between the test and retest results for 22 individuals. The correlation value between FFQ screener software dietary sodium consumption and 24-hour urine sodium test was 0.6 (p0.000) for criterion validity. The correlation between the FFQ screener software and 3-day recall sodium intake was 0.3 (p0.0001). A significant correlation exists between sodium intake, preferences for low-sodium foods, and previous salt reduction (p0.05). FFQ sodium was unrelated to salting after cooking, salted meal selection, or sodium on product labels (p > 0.05). Conclusions: Software FFQ screeners are a valid and reliable method for measuring sodium intake. Validation assures a reliable and innovative approach to measuring sodium in the diet. Photo-based portion size estimation improves the accuracy of diet evaluation.
- ItemPERFORMANCES OF WET GRANULATED LACTIC ACID BACTERIA FOR THE DIRECT FERMENTATION OF WHEAT DOUGHS(An-Najah National University, 2018-07-24) Dabous, AzzaBackground: Sourdough is a mixture of flour and water, which is fermented by the action of lactic acid bacteria (LAB) and yeasts. These microorganisms usually come from flour, dough ingredients or the environment. The selection and preservation of LAB suitable for industrial or artisanal bread making represents a useful tool to better address the biotechnology choices of the bakery industries. Thermal drying is one of the most popular methods used in the production of dried sourdough starters. However, drying may injury LAB in many ways. Material and methods: This study assessed the fermentation ability of 43 bacteria strains to be use as suitable sourdough starters, then the best fermentative strains were further classified and combined based on their biochemical and genotypic criteria. In the second phase of the study, we compared the drying effect of wet granulation and freeze drying method on the viability of starter culture. Results: Wet granulation was successful in obtaining better leavening height in comparing with fresh cells (p value < 0.05), while the leavening height obtained by using freeze dried sourdough starter was lower than the fresh cells. Wet granulation process has very little effect on the viability of microbial cells and doughs obtained were characterized by a considerable amount of lactic acid like the fresh cell starters. Sensory analyses univocally indicated that breads obtained by using the starter culture, above all as fresh cells, resemble those produced by means of the natural sourdough. Indeed, further efforts are required to point out a better strategy to stabilize the microbial combination during its shelf-life.
- ItemEffect of vacuum packaging combined with natural additives on the shelf life and quality traits of fresh thyme(Doaa Kanan, 2019-12-08) Kanan, DoaaGreen thyme (Za’atar) is one of favorite herbs among Palestinian’s garden. It refers to genus Origanum of Lamiaceae family. This study aim to extend the shelf life fresh green thyme by hurdle technology by employing vacuum packaging technique combined natural additives (onion, sumac, lactic acid and oil and salt) then stored at room and refrigerated temperature to study the effect of natural additives combined with vacuum packaging on the physochemical properties of green thyme including color, taste, flavor, pH, chemical compositions and how they change during 42 days. Moreover, Study the probability of growth of Clostridium Botulinum in green thyme samples under anaerobic condition by using microbiological challenge test. Lactic acid was the most effective to keep different quality traits during storage. Refrigerated conditions were the best storage condition to extend the shelf life of thyme products. Green thyme leaves are very valuable agricultural product in Palestine. Until now, this product is not exploited to the export market due to short shelf life; the findings of this study may contribute to increase the potential of this product for export market.
- ItemConsumer Sensitivity and Freshness Evaluation of Bakery Products(An-Najah National University, 2019-07-25) Zidan, SouzanFocaccia is a typical bakery product in Italy, which is highly appreciated for its sensory characteristics and has its own market. Its quality deterioration during storage is caused chiefly by various deteriorative events which include the loss of crispness linked to high water activity, starch retrogradation and lipid oxidation. The loss of freshness in bakery products negatively affects consumer’s liking and the product’s quality. The freshness perception of a food during its shelf life depends on both the sensory properties of the food and the consumer’s ability to perceive a sensory deterioration. Consumers differ in their abilities to perceive tastes and textures, and these perception differences may lead to different preferences. Sensory methods can be used to understand individual sensitivity of consumers. The main purpose of this research is to evaluate consumer perception of focaccia samples stored at different times and to explore whether there is an association between consumer sensitivity and the perception of focaccia samples. Focaccia with two different toppings (tomato &olives (F1), and frozen onion with oregano (F2)) were considered in this research. All samples were stored for 7, 15, 30, and 60 days at 20ºC. Consumer sensitivity to taste, odor and texture were evaluated by using PROP status test, odor pens test, and hardness test, respectively. Weibull distribution was used to describe the rejection function. CATA method was used to determine sensory attributes of focaccia samples. Nighty-nine consumers participated in the consumer test. Consumers were asked to eat each sample of focaccia and to answer the question:" Would you normally consume/buy focaccia? Yes or No?". They were asked also to choose the most suitable attributes that can describe the samples and to evaluate their liking by using 10cm scale anchored from “the most unpleasant imaginable” to “the most pleasant imaginable”. From survival analysis, it was observed that the acceptance percentage for samples stored for 60 days was slightly higher for samples F2 (50%) compared to (47%) for samples F1. The shelf life was estimated as the storage time that corresponded to 50% consumers acceptance in 58 ±6 d, and 61±5 d, respectively for samples F1 and F2. For sample F1, CATA questions results showed that there are significant differences for both negative attributes (stale, dry tomato, hard, raw dough) and positive attributes (soft, typical focaccia flavor, sweet tomato, fresh tomato). In the same way, for sample F2, CATA questions results showed that there are significant differences in terms of both negative (stale, hard, onion taste) and positive (soft, pungent onion taste) attributes. For both types of samples, it was also noted that fresh samples were liked as the as those stored for 60 days. Our findings also showed that there is no significant association between liking scores of focaccia and socio-demographic variables (age and gender). We recommend that the current study should be followed up with larger number of consumers. Future studies should also assess participants’ psychological and personality traits.