The Scientific Society of Food Industries, Alexandria, Egypt.Alexandria Journal of Food Science and Technology1687-39203120060601Expression of the Pediococcus acidilactici ldh L gene in Propionibacterium freudenreichii var. shermanii LAG16424T191961710.21608/ajfs.2006.19617ENJournal Article20181121As a cloning vector for transformation in Propionibacterium sp., pPK705 shuttle vector was experimented,<br />where it consists of the indigenous plasmid of Propionibacterium acidipropionici E214 (pRG01),<br />plasmid pUC18 and the hygromycin resistance gene (hyg B). A 1.2 Kb BamHI-EcoRI DNA fragment encoding<br />ldh L gene of Pediococcus acidilactici DG302 was cut from plasmid pGID150 and further subcloned in<br />pPK705. Transformation and expression of the ldh L gene of pediococci in NAD+-independent LDH Propionibacterium<br />freudenreichii var. shermanii LAG16424T was confirmed. The absolute L (+) LDH enzyme activity<br />was found to be (25.67 to 42.79 IU/ml) for Propionibacterium transformants cell free extract. Twenty Propionibacterium<br />transformants were further inoculated in skimmed milk, where curdling was detected after 48 h<br />with one of the prominent transformants. After 144 h, all transformants coagulated skimmed milk as compared<br />to parental bacterial strain. Maximum % of lactic acid produced by Propionibacterium transformants was<br />0.79 % as lactic acid after 96 h. Further proof for the expression of NAD+-dependent L (+) LDH through the<br />transformed ldh L gene was confirmed by polyacrylamide gel electrophoresisThe Scientific Society of Food Industries, Alexandria, Egypt.Alexandria Journal of Food Science and Technology1687-39203120060601Frequency of Fast Food Consumption: Effects on the Nutritional Status of Groups Aged 12-22 Years11181961810.21608/ajfs.2006.19618ENJournal Article20181121Fast food consumption has increased greatly particularly among youth. The attraction of eating<br />fast food items makes the youth gain weight and badly affects their health. To study the effect of frequency<br />fast food consumption, 868 subjects (males and females) aged 12-22 years were selected randomly<br />from clubs and youth centers in Alexandria city. Socio-demographic characteristics, frequency and<br />attitude toward fast food consumed, weight, height and body mass index (BMI) were recorded. Dietary<br />intake was estimated using 24 hours recall for 3 consecutive days. It was found that consumption of fast<br />food was prevalent between both genders. Frequency of consumption of fast food showed that 38.7% of<br />subjects eat fast food frequently (group1) and 61.3% of them eat fast food less frequently (group2). Proportion<br />of subjects with BMI greater than 85th percentile was significantly higher among group1 (36.9%)<br />than group 2 (28.9%) indicating a risk of overweight and obesity of subjects, who eat fast food frequently<br />compared with those who eat fast food less frequently, consumed higher intake of energy, protein, fat and<br />carbohydrate. Mean energy intake of males and females in group1 and group2 covered (85.3%, 78.1%)<br />and (92.3%, 84.1%), respectively of RDA, while protein intake exceeded the recommendation for both<br />groups. Television advertisements have a significant influence on fast food consumption. Only 22% of<br />group1 and 31.2% of group2 believed that fast food can cause disease cases, while 41.7% of group1 and<br />43.2% of group2 believed that consumption of fast food is harmless. Animal protein was consumed in<br />high proportion of subjects eat fast food frequently, while consumption of plant protein was high among<br />those eat fast food less frequently. Public health measures should be aimed at limiting the amount and<br />frequency of fast food consumption. This could include nutritional education campaigns, regulation of<br />fast food advertising, getting rid of fast food restaurants in schools, and increasing healthy food vendings<br />in youth centers, clubs, schools, and education foundationsThe Scientific Society of Food Industries, Alexandria, Egypt.Alexandria Journal of Food Science and Technology1687-39203120060601Deep-Fat Frying of Potatoes in Palm Oil in Relation to Quality Characteristics Assessment19281961910.21608/ajfs.2006.19619ENJournal Article20181121Sensory and chemical attributes of palm oil used for repeated and discontinuous deep-fat frying of<br />potato chips at elevated temperatures were followed. Polyunsaturated fatty acids (PUFAs) decreased in<br />direct proportion to frying times, whereas saturated FAs were found to inversely increase. A strong degree<br />of correlation (R2) was found between C18:2/C16:0 ratio and the frying time. Free fatty acids were released<br />and their concentration in the palm oil often increased with repeated use. From acid values and polar<br />compounds contents of the used palm oil, it was obvious that thermoxidative alterations took place<br />mainly instead of the hydrolytic process. Frying palm oil was also analyzed for ultraviolet absorption<br />(A232 and A268), peroxide value (PV) and thiobarbituric acid (TBA) value during repeated and discontinuous<br />deep-fat frying. The correlation coefficients (r) between heating times and A232, A268, PV and TBA<br />values were 0.82 , 0.45 , 0.42 and 0.95 , respectively . During frying stages, both A400 and A450 of the used<br />palm oil were measured. Frying times were highly correlated with the steady and proportional increment<br />in A400 and A450. Sensory analysis of the palm oil used in potatoes frying exhibited that quality deterioration<br />has taken place with the progression of frying times. During frying process, there was an inverse relationship<br />between odour and colour sensory scores and frying times with a correlation coefficients of r =<br />–0.9204 and –0.9667, respectively. Various prediction models for assessing accurately frying times using<br />different dependant variables were established.The Scientific Society of Food Industries, Alexandria, Egypt.Alexandria Journal of Food Science and Technology1687-39203120060601Applications of Biosensors to Analysis and Quality Control of Foods: An Overview29401962010.21608/ajfs.2006.19620ENJournal Article20181121Biosensors have been described as the offspring of the marriage of biology and electronics. A biosensor<br />is an analytical device consisting of a biocatalyst (enzyme, cell or tissue) and a chemical or physical<br />transducer (electrochemical, mass, optical and thermal) which can convert a biological or biochemical<br />signal or response into a quantifiable electrical signal. Modern biosensors evolved from the combination<br />of the aforementioned two disciplines, with electronics/ information technology exemplified by micro circuits<br />and optical fibers, and biology exemplified by molecular biology in the form of enzymes and antibodies.<br />Biosensors technology provides a new, substrate specific method enabling repeated measurements<br />and possibility of on-line analysis for the process control in the food industry. It is obvious that on-line<br />measurement is very important for the quality control and quality assurance (QC/QA) and hazard analysis<br />at critical control point (HACCP). It is worth to mention that biosensors are very important analytical<br />tools to detect any intended pollution of drinking water via bioterrorism. Biosensors are characterized by<br />easy operation, rapid response and long stability. Such advantages suggested that biosensors can be used<br />as economical analytical tools in the area of food analysis and quality control.<br />The present article deals mainly with the applicability of biosensors in the area of food analysis and<br />quality control. For instance, many components in foods can be determined by means of biosensors.<br />Meanwhile, the most important applications of biosensors in the area of food quality control include: microorganisms<br />detection, sensory analysis, electronic tongue and nose, quality control of modified atmosphere<br />packages, fish freshness analysis, meat and milk quality.The Scientific Society of Food Industries, Alexandria, Egypt.Alexandria Journal of Food Science and Technology1687-39203120060601Effect of Some Amino Acids on CO2 Production by Leuconostoc mesenteroides subsp. dextranicum Isolated from Raw Milk191962110.21608/ajfs.2006.19621ENJournal Article20181121بکتريات منتجة لحامض اللبن، وهي غير متجانسة التخمر ويمکن استعمالها في Leuconostoc sp تعتبر أفراد جنس<br />المسبب للثقوب. تم في هذه الدراسة عزل وتوصيف سلالتين CO صناعة الأجبان الزرقاء نظرا لإنتاجها للنکهات وغاز ال 2<br />Leuconostoc أنهما عبارة عن (L لهذه البکتريا من الحليب الخام للبقر، وتبين بعد المطابقة مع السلالة القياسية ( 4<br />لهاتين السلالتين، وقد أظهرت CO ودرست بعدها حرکية الحموضة وحرکية انتاج ال 2 mesenteroides subsp. dextranicum<br />في تکوينها للحموضة بواقع 43.43 ملليمول من اللاکتات في حين کانت کمية غاز ثاني أکسيد HB النتائج تفوق السلالة 1<br />الکربون المنطلقة 7.27 ملليمول وذلک بعد سبع ساعات من التحضين وبمعامل ارتباط 0.94 ، کما درست في ذات الوقت حرکية<br />باستخدام جهاز CO النمو حيث سجل توافق کبير بين الحرکيات الثلاث. کما ُقدر فى هذه الدراسة النشاط النوعى لتوليد غاز ال 2<br />للسلالات الثلاث، وکانت الأحماض الأمينية المحفزة لزيادة توليد غاز ثاني أکسيد الکربون هي الفالين، التريبتوفان، (Warburg)<br />سيستئين والفينايل ألانين وکانت قيم النشاط النوعي لتوليد الغاز للسلالتين المعزولتين کنسب مئوية من قيم النشاط النوعي<br />،%60.7 ،% تجاه الأحماض الأمينية ذات التأثير الإيجابي على النحو الآتي: 30.27 L المتحصل عليها للسلالة القياسية 4<br />وذلک للأحماض الأمينية .HB 21.32 % بالنسبة للسلالة 2 ، %22.85 ،%0 ،% و 0 HB %16.58 بالنسبة للسلالة 1 ، %90.42<br />التالية: الفالين، التربتوفان، السيستئين والفينايل ألانين على الترتيب.