Nutrition and Food Technology
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- ItemMOLECULAR DETECTION OF LISTERIA MONOCYTOGENES IN FRESH VEGETABLES VIA RT-PCR IN THE WEST BANK(An-Najah National University, 2024-02-12) Al-Athamneh, DaniaListeria monocytogenes is an emerging foodborne pathogen that can be transmitted by a wide range of food items. This study aimed to evaluate the existence of L. monocytogenes in freshly selected vegetables (lettuce, parsley, watercress, spring onion, carrot juice) in five governorates in the West Bank, Palestine using both conventional and molecular methods. A total of 150 fresh vegetable samples were bought from hypermarkets and street food hawker stands. The presumed isolates were differentiated biochemically and were further confirmed by Real-Time Polymerase Chain Reaction (RT-PCR) targeting 16S rRNA gene for Listeria spp. and the hly gene, which is specific to L. monocytogenes. The results showed that 71% of the examined fresh vegetable were positive for L. monocytogenes based on the media's selectivity and the colonies' morphological characteristics. Percentages distribution of L. monocytogenes in the fresh vegetables were 66%, 70, 70, 73 and 73% for lettuce, watercress, spring onion, carrot juice, and parsley, respectively. On the other hand, statistical analysis of RT-PCR results indicated significant differences in L. monocytogenes levels among vegetable samples within the same governorate. In Tulkarm, the highest levels were found in carrot juice, while the lowest were in lettuce. Also in Nablus, the highest levels were found in carrots juice, while the lowest were in lettuce and watercress. Also, Ramallah, Bethlehem, and Hebron, each the highest in spring onion, while the lowest were lettuce. Additionally, indicated comparison of L. monocytogenes levels across cities for selected of vegetables significant differences that lettuce had the highest prevalence in Bethlehem, parsley in Bethlehem, also watercress, spring onion, carrot juice each the highest in Hebron. In conclusion, this study has demonstrated a high prevalence of Listeria in fresh vegetables using both methods however, the molecular method was more sensitive and reliable for listeria confirmation. Contamination by Listeria in hypermarkets and street food as well is of great public concern and justifies more observation and strict regulations to reduce the frequent contamination of fresh vegetables with L. monocytogenes.
- ItemINNOVATING DAIRY ALTERNATIVES: THE PRODUCTION AND EVALUATION OF PLANT-BASED YOGURT SUBSTITUTES(An-Najah National University, 2025-02-26) Ibrahim, AyahBackground The demand for plant-based food alternatives has increased in recent years, driven by growing health consciousness, and environmental concerns. Among these alternatives, plant-based yogurt has become increasingly popular as a dairy substitute. Objectives The primary objective of this study is to evaluate the impact of blending four distinct plant-based milk varieties (oat milk (OM), almond milk (AM), coconut milk (CM), and quinoa milk (QM)) at varying concentrations on the physicochemical properties and sensory and nutritional characteristics of plant-based yogurt following fermentation with lactic acid bacteria. Methodology Various plant-based milks were selected for yogurt production and blended at different ration (T1: 30% OM, 30% AM, 20% CM, 20% QM, T2: 30% OM, 20% AM, 40% CM, 10% QM, T3: 50% OM, 25% AM, 15% CM, 10% QM, T4: 30% OM, 30% AM, 10% CM, 30% QM, T5: 25% OM, 20% AM, 35% CM, 20% QM). The blended plant-based milk were fermented by using (Lactobacillus Bulgaricus and Streptococcus Salivarius subsp. Thermophilus) at 45°C for 6 h. To avoid the Syneresis phenomena stabilizers, pectin and xanthan gum and their mixture was added. The quality of the milk was assessed through pH measurements, total titratable acidity, and zeta potential particle size and polydispersity index were also measured to ensure the stability of the formulations. Blended plant-based yogurt were evaluated for their viscosity and sensory evaluations and acceptability index. Moreover, the nutritional composition of the blended plant-based yogurts was analyzed. Results The plant-based milk was successfully extracted and blended in different ratios. Fermentation ended when the pH reached 4.6. Before fermentation, the acidity ranged from 0.04% to 0.6% as lactic acid, increasing to 0.15%–0.2% during fermentation. T1 had the highest acidity due to its 30% oat and 30% almond milk, while T2 had the lowest with 40% coconut milk and 30% oat milk. Stabilizer addition influenced zeta potential and particle size. Xanthan gum alone significantly improved zeta potential and reduced particle size in T1 and T2 compared to pectin alone or their combination. However, pectin and xanthan gum together further reduced particle size and enhanced stability in T3, T4, and T5. T5, with 35% coconut and 25% oat milk, was the densest and thickest, whereas T1 had the lowest viscosity. Sensory analysis showed that T3 and T5 scored highest in appearance and viscosity, while T5 had the highest overall acceptance. Nutritionally, T1 had the lowest calorie content (49 kcal), while T1, T3, and T4 had the highest protein content (1.2%–1.3%). Discussion Higher acidity in T1 is likely due to increased fermentable sugars in oat and almond milk, while T2's lower acidity may be attributed to coconut milk’s lower sugar content. Stabilizers influenced texture, with xanthan gum improving stability and the pectin-xanthan combination further enhancing viscosity. Sensory results aligned with physicochemical findings, with T5’s balanced composition (coconut, oat, almond, quinoa) yielding optimal mouthfeel and texture, leading to higher acceptance. The low-calorie content of T1 may appeal to health-conscious consumers, while T1, T3, and T4’s higher protein content suggests nutritional benefits. Overall, formulation significantly affected fermentation, stability, and acceptability, highlighting the potential of optimized plant-based yogurt. Conclusions In this study, oat, almond, coconut, and quinoa milk were combined to successfully create blended plant-based yogurt. It is possible that this plant-based yogurt will be a good substitute for dairy yogurt, especially for customers who are vegan, lactose intolerant, or intolerant to dairy proteins. Upgrading formulations for commercial use and increasing production should be the main goals of future research.
- ItemTHE DEVELOPMENT AND VALIDATION OF IMAGE-BASED QUESTIONNAIRE FOR WEIGHT BIAS AND STIGMATIZATION ASSESSMENT AMONG SCHOOL-AGED CHILDREN: A CROSS-SECTIONAL STUDY(An-Najah National University, 2024-11-14) Bustami, LinaBackground: Obesity is a well-recognized complex global epidemic. There are multiple causes and complications of obesity, physical and psychological ones. The experiences of weight bias and stigmatization against individuals with obesity is one challenge, which often goes unnoticed. Weight stigma is associated with many negative outcomes, including psychological disturbances, eating disorders, weight gain, and avoiding physical activity. Weight stigmatization is prevalent among different age groups, and was identified to be high among children at a young age. Objective: The main purpose of the study is to assess the percentage of weight bias and stigmatization among school-aged children, through the development of an image-based tool that is suitable for children’s cognitive abilities. This study is conducted as a step-1 for further educational intervention studies to reduce weight stigma among children. Methodology: A cross-sectional study was conducted on 150 children aged 6-9 year in three schools in Nablus City, Palestine: Pioneers Baccalaureate School, Ethar School (2nd grade), and UNRWA school. The assessment was carried after the development and validation of a questionnaire, designed specially to assess weight stigmatization percentage among children at early age. Result: 71% of children attributed “Ugly” adjective to characters with overweight compared to only 8.7% to those with under and normal weights. Also, 89% of children chose the character with overweight for “lazy” trait, 72% for “careless”. In contrast, 81.9%, 81.9%, of participants chose the figures with underweight and overweight for “loved”, and “good”, adjectives, respectively. Only one child chose the figure with overweight as a best friend. 84.6% (n=126) chose figures with under or normal weights as the one they like the most, while the one with overweight was chosen only 1.3% of time (n=1.3). Additionally, 81.9% (n=122) of children agreed with the statement that the character with overweight eats more than required, whereas only 18.1 (n=18.1) disagreed. 61.7% expressed their agreement with “I think he/she sleeps a lot”. In addition, 59.1% (n= 88) of children disagreed that the character can’t lose weight even when he/she stops overeating. Conclusion: The study indicated a high percentage of weight stigmatization among school aged children in the current study. Stereotyping, weight bias and judgmental attitudes towards individuals with overweight were common in all the three sections of the developed image-based questionnaire. These findings highlight the importance of acting towards reducing weight stigma among children, and suitable educational programs are recommended to be established. Keywords: weight stigma, weight bias, obesity, children, tool validation
- 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.