Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : POSTHARVEST TECHNOLOGY OF VEGETABLE PLANTS BY-PRODUCT

Auteur : MOSTAFA, EMAN MOHAMED TORK GABER.

Etablissement de soutenance : Ain Shams University

Grade : Doctor of Philosophy (PhD) 2022

Résumé partiel
Fruit and Vegetable peels wastes are generated from household and food-processing industries. Up to one third of the volume of fruit and vegetables are in form of peels, seeds, and skins, which is discarded during preparation and processing resulting in by-products. Production of by-products is increasing every day and these plant materials represent growing problems due to microbial spoilage that limits its further exploitation. According to the Food and Agriculture Organization of the United Nations (FAO), about 1.3 billion tons of foods are wasted worldwide each year, which accounts for one third of total food industry production. Then, there are great challenges, such as to minimize wastes arising from processing operations and to utilize the by-products and to treat and dispose the wastes along with sustainable production. Fruit and vegetable peels are valuable by-products due to their content of many nutrients and antioxidants ; thus extracts of peels could be used in formulation of food products for fortification with those compounds. This study has been done on three by-products of vegetable crops. Aimed to identify the nutritional quality of peels of watermelon, eggplant and potato with regards to its content of antioxidants compounds, fiber, protein, fat, carbohydrate and nutrition minerals. Besides, screening of phytochemical compounds and food safety analyzes. In addition to, feasibility study of using these by-products as a substitute for flour in making some baked products and making sensory evaluation of these products. These by-products dry powder was used partially substituted for wheat flour in produced bakery products at different levels (5, 10 and 20%). The present results cleared that watermelon rind is a good source of the dietary fiber (" " 16%) followed by eggplant peels (" " 14%) and potato (" " 8%) ; and nutrition minerals - especially potassium which was 5.4 % in eggplant peels, 5.2 % in potato peels and 4.1% in watermelon rind. for antioxidants compounds, watermelon was the higher content followed by eggplant then potato. And according to food Safety tests results, it could be said that all fresh samples under study were safe and can be used in food products. Also, storage experiments were done and samples were analyzed every month for a period of three months. These experiments have been done at two temperatures for storage, one below zero (-20 + 2o) in polyethylene packages and the other at room temperature (25 + 2o) in burlap bags. The obtained results show that antioxidant activity, total phenols and flavonoids were decreased with the passage of time and at both temperatures under study and the concentrations at room temperature were lower than those at the freezing point. For the proximate analysis, the protein analysis only changed slightly compared to the rest of the analysis, which was not noticeably affected at both temperatures with the passage of the storage period. The results of the analyses of the elements also did not witness a noticeable effect on storage or when changing the degree of storage.

Présentation étendue (EULC)