The Influence of Abrasive Pretreatment on Hot Air Drying of Grape
The Influence of Abrasive Pretreatment on Hot Air Drying of Grape作者机构:Department of Industrial Engineering University of Salerno Fisciano Italy School of Chemistry Physics and Mechanical Engineering Faculty of Science and Engineering Queensland University of Technology Brisbane Australia Institute for Microelectronics and Microsystems Napoli Italy Department of Chemical Engineering Materials Environment University of Rome “La Sapienza” Roma Italy
出 版 物:《Food and Nutrition Sciences》 (食品与营养科学(英文))
年 卷 期:2015年第6卷第3期
页 面:355-364页
学科分类:1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学]
主 题:Grape Drying Raisin Abrasive Pretreatment Sugar Content Shrinkage Texture Rehydration
摘 要:The drying of grapes is a more complex process compared to the dehydration of other agricultural materials due to the necessity of a pretreatment operation prior to drying. Grape drying to produce raisins is a very slow process, due to the peculiar structure of grape peel, that is covered by a waxy layer. Its removal has been so far carried out by using several chemical pre-treatments. However, they cause heterogeneity in the waxes removal and create microscopic cracks. In this paper an abrasive pretreatment for enhancing the drying rate and preserving the grape samples is proposed. Two cultivars of grape were investigated: Regina white grape and Red Globe red grape. The drying kinetics of untreated and treated samples were studied using a convective oven at 50°C. Fruit quality parameters such as sugar and organic acid contents, shrinkage, texture, peel damage (i.e. by SEM analysis) and rehydration capacity were studied to evaluate the effectiveness of abrasive pretreatment on raisins. Abrasive pretreatment contributed to reduce drying time and rehydration time. The treated and untreated dried grapes were significantly different (p 0.05) in sugar and in tartaric acid content. On the contrary, no significant differences (p 0.05) in malic and citric acids and in texture properties between untreated and treated samples were observed.