Mansoura University, Faculty of AgricultureJournal of Food and Dairy Sciences2090-36504720130701INVESTIGATION THE DRYING CHARACTERISTICS OF SOME CITRUS PEELS TO UTILIZE IN PREPRATION OF CAKES3433587207710.21608/jfds.2013.72077ENM. A.Abd El-GaleelFood Tech. Dept., Fac. of Agric., Kafrelsheikh Univ., Egypt.M. I.ShoughyAgric. Eng. Res. Inst. (AEnRI), Dokki, Giza, Egypt.Journal Article20200219 This work was carried out to investigate the effect of drying temperature and residual moisture content on the quality of orange and mandarin peels. The changes in moisture content of citrus peels (CP), drying rate and specific energy consumption at various drying temperature was examined. The test samples were dried in a laboratory scale hot air dryer at a constant air velocity of 1m/s and air temperature in the range of 40–70<sup>o</sup>C. The effect of drying temperature and residual moisture content on gross chemical composition, vitamin C, carotenoids and essential oils of citrus peels was studied. Cakes prepared from blendes containing different proportions (0, 10, 15 and 20%) of dried orange and mandarin peels were also evaluated for chemical composition and sensory attributes. The results indicated that, the drying temperature was very effective in removing moisture from citrus peels. The orange peels had the highest drying rate than that of mandarin peels. The time required for drying citrus peels was considerably decreased with the increment in the drying air temperature. The simple exponential equation satisfactorily described the drying behavior of citrus peels as indicated by the higher correlation coefficients. The drying time was decreased by 50% and specific energy consumption decreased by about 28.5% with increasing drying temperature from 40 to70<sup>o</sup>C for drying citrus peels. Meanwhile, the optimal drying temperature was 60°C to reach 10±0.2%, w.b, moisture level, which saved energy consumption and reduced drying time as well as decreased the losses of vitamin C, carotenoids and essential oils of citrus peels. In addition, overdrying to reach final moisture level of 5.4±0.2% with drying air temperature of 70<sup>o</sup>C increased the losses of vitamin C, carotenoids and essential oils of orange peels by 80.5, 13.5 and 62.5%, while for mandarin peels the losses increased by 77.9, 14.2 and 64.3, respectively compared to fresh samples. Incorporation 15% of dried orange and mandarin peels in cakes increased dietary fiber by 33.5 and 29.6%<em>, </em>ether extract by 2.9 and 4.6% and ash by 30.6 and 29.0%, respectively, while protein and total carbohydrates contents were slightly decreased. Highly acceptable cakes could be obtained by incorporating 15% of orange and mandarin peels dried to about 10% moisture content and they can be used as value-added food ingredients.https://jfds.journals.ekb.eg/article_72077_8b177305887049c065c858af31e57d14.pdfMansoura University, Faculty of AgricultureJournal of Food and Dairy Sciences2090-36504720130701EFFECT OF CONCENTRATION PROCESS AND STORAGE PERIOD ON QUALITY PROPERTIES OF SOME FRUIT AND VEGETABLE CONCENTRATES3593727207810.21608/jfds.2013.72078ENM. T.ShalabyFood Industries Dept., Fac. Agric., Mansoura University, Egypt.Faten Y.IbrahimFood Industries Dept., Fac. Agric., Mansoura University, Egypt.S. M.El-ShehawyFood Industries Dept., Fac. Agric., Mansoura University, Egypt.M. N.IbrahimFood Industries Dept., Fac. Agric., Mansoura University, Egypt.Journal Article20200219This study was carried out to follow up quality changes occurred in some fruit and vegetable concentrates during processing and storage. Orange, apple and tomato concentrates were evaluated for some quality attributes such as TSS%, acidity, vitamin C, carotene, pH and specific gravity. The obtained results indicated that vitamin C content of orange concentrate was decreased as a result of both the concentration process and storage period. While, it was increased from 0.38 mg/100 ml. in fresh apple to 1.33 in apple concentrate. As for tomato concentrate, reducing sugar content increased from 1.277% in fresh to 6.55% after three months of storage. Finally, it could be stated that concentration process and storage period highly affected the chemical and physical quality properties of the studied concentrates.https://jfds.journals.ekb.eg/article_72078_864a850bb4544064e29d9164757a20fa.pdfMansoura University, Faculty of AgricultureJournal of Food and Dairy Sciences2090-36504720130701STUDIES ON THE EFFECT OF BROWNING REACTIONS ON SOME PRODUCTS OF FIG (Ficus carica).3733857207910.21608/jfds.2013.72079ENMona M.KhalilFood Industries Dept. Fac. of Agric. Mansoura Univ. EgyptFaten Y.IbrahimFood Industries Dept. Fac. of Agric. Mansoura Univ. EgyptA. M. M.Nezam EL DinFood Technology Research Inst., Agric. Res. Center, Giza, EgyptK. M.AtyaFood Technology Research Inst., Agric. Res. Center, Giza, EgyptJournal Article20200219 This study was carried out on fig products (syrup, jams and sheets) to investigate the effect of industrial food processing on browning reactions. During processing some changes in fig products are occurred with respect to colour and final aspects change. Thermal treatments during the preparation of fig syrup can effect on its quality through the non-enzymatic browning reactions. Different indicators were assayed to determine the extent of browning which include absorbance measurements at 420nm, colorimetric evaluations and determinations of sugar, furfural, hydroxymethylfurfural (HMF) and total phenols in the final product. hydroxymethylfurfural (HMF) content was increased after processing in fig syrup and sheets. On the other hand, total phenols and total flavonoids were decreased after processing in all products that refer to the activity of polyphenoloxidase. Fig sheets treated with SO<sub>2 </sub>had higher color score compared with control sheets. Fig jam treated with lemon juice had higher taste and odor scores compared with fig jam produced from the residue of fig juice concentrate. Fig syrup had desirable organoleptic characteristic scores.Regarding to free amino acid concentration, there is a decreased after manufacturing processes in some amino acids as valine, aspartate, glutamate, alanine, argnine, and lysine. This decrease reflects the consumption of these free amino acid during Millard reactions.https://jfds.journals.ekb.eg/article_72079_9b8840f954ab00c33179d6ba61447663.pdfMansoura University, Faculty of AgricultureJournal of Food and Dairy Sciences2090-36504720130701ANTIOXIDANT AND ANTIMICROBIAL ACTIVITY OF POMEGRANATE (Punica granatum L.) FRUIT PEELS EXTRACT ON SOME CHEMICAL, MICROBIOLOGICAL AND ORGANOLEPTICAL PROPERTIES OF YOGHURT DURING STORAGE.3874007208010.21608/jfds.2013.72080ENM. E.Abd El – AzizDairy Dept., Fac. of Agric., Mansoura Univ., Egypt.Rania El-GammalFood Industries Dept., Fac. of Agric., Mansoura Univ., EgyptM. M.Abo-sreaFood Industries Dept., Fac. of Agric., Mansoura Univ., EgyptFaten I.YoussfFood Industries Dept., Fac. of Agric., Mansoura Univ., EgyptJournal Article20200219Pomegranate (<em>Punica granatum)</em> fruit peels was investigated for its phenolic compounds, antioxidant and antoxidative activity on L.A.B in yoghurt during cold storage . Results of chemical composition being 7.15 %, 1.22 % 0.65 % and 85.04 % for moisture, protein, crude fat and carbohydrates respectively. Total phenolic compounds were 42.62 mg gallic acid / g. Data of HPLC revealed that ten compounds were identified namely catechin , gallic and - chlorogenic acid being 138.71, 111.68 and 92.39% , Moreover catechol and caffein were 84.36 and 44.47 % and other trace compounds namely coumarin, cinnamic , chrysin, caffeic and ferulic . Radical scavenging activity DPPH for the aqueous extract was 90.97 %,compared with TBHQ 94.1% as synthetic one. Pomegranate peel extract explored considerable inhibitory effect of each of lactic acid bacteria, coliform group and <em>Staph. Sp.</em>
The increase aqueous extract of pomegranate peel from 1to 5 % lead to an inhibitory effect on LAB and other tested pathogenic bacteria. 1 % of extract was appropriate for the viability of Lactic acid bacteria which was above 30 × 10<strong><sup>6</sup></strong> c.f.u ⁄ ml. In addition, using of 1 %, 0.75, 0.5 and 0.25% on yoghurt processing was acceptable for the chemical, microbiological and organoleptical properties of the resultant yoghurt. Moreover, the ratio of 0.75 % was more acceptable, comparing with other added doses. https://jfds.journals.ekb.eg/article_72080_0cf26d479c0b7e81d8999f48ec863372.pdf