Effects of Electron Beam Irradiation on Physical, Textural, and Microstructural Properties of "Tommy Atkins" Mangoes (Mangifera indica L.)

This research focused on determining the dose levels suitable for electron beam irradiation of mangoes without detriment to the fruit's quality characteristics. Physicochemical, textural, respiration rates, microstructural, and sensory characteristics of “Tommy Atkins” mangoes irradiated at 1.0, 1.5, and 3.1 kGy using a 10 MeV (10 kW) linear accelerator with double‐beam fixture were determined. Fruits were stored at 12 °C and 62.7% RH for 21 d and evaluated at days 0, 5, 10, and 21. Nonirradiated mangoes served as controls. Irradiation did affect the textural characteristics of mangoes at doses higher than 1.0 kGy. Mangoes exposed to 1.5 and 3.1 kGy were softer and less stiff throughout storage. The radiation‐induced softening of the fruits may be associated with changes in the structural cell such as cracks and depressions on the surface and the breakdown of the cells and its components. Irradiation at 3.1 kGy affected the color of mangoes by the end of storage. Doses up to 1.5 kGy kept respiration rates at a normal level. Irradiation did not affect the specific gravity of mangoes, a parameter associated with fruit maturity levels. No effect of irradiation on pH, water activity, moisture content, acidity, and juiciness of mangoes was detected at the dose levels used in this study. Only fruits irradiated at 3.1 kGy were unacceptable to the sensory panelists in terms of overall quality, texture, and aroma. Electron beam irradiation of “Tommy Atkins” mangoes at 1.0 kGy is the recommended treatment to maintain the overall fruit quality attributes.     

热加工对淀粉结构和理化性质的影响研究进展（网络首发、推荐阅读）

淀粉是一种非常重要的植物多糖,同时也是重要的食品生产加工的工业原料。天然淀粉耐热、耐剪切、耐酸能力差,且易回生,需要对淀粉进行物理改性、化学改性和酶改性。在淀粉改性尤其是化学改性中,化学试剂易残留于改性淀粉中,所以快速、安全的物理改性越来越受到大家关注。而物理改性中,热加工改性应用较为广泛。通过概述六种常用的热加工改性技术对淀粉结构及性能的影响,旨在为热加工改性淀粉理化性质的研究提供理论参考,以期能为特定需求淀粉的生产研发提供一定的理论依据。     

Effect of treatment with α‐galactosidase,tannase or a cell‐wall‐degrading enzyme complex on the nutritive utilisation of protein and carbohydrates from pea (Pisum sativum L.) flour

The effect of treatment with α‐galactosidase, tannase or a cell‐wall‐degrading enzyme complex under optimal conditions of pH, temperature and length of incubation time on the chemical composition and nutritive utilisation of protein and carbohydrates from pea (Pisum sativum L.) flour was studied. Soaking of pea flours in combination with enzyme treatment led to reductions of 77–90% in the levels of α‐galactosides, and of 60–80% in the levels of trypsin inhibitor activity, increasing the content of total available sugars, which was highest in the pea flour treated with the cell‐wall‐degrading enzyme complex. All the treatments assayed caused a significant improvement in daily food intake, whereas the nutritive utilisation of protein was not increased in any of the pea products tested when compared to the raw pea flour. However, all the soaking and enzymatic treatments led to a significant improvement in daily weight gain associated with a higher dietary intake of food and total available sugars. Copyright © 2007 Society of Chemical Industry