Drying kinetics and microbiological quality of green onions

ABSTRACT Green onion (Allium fistulosum L.) is widely consumed and traded in Brazil as condiment. Because of the high yields in the region of Volta Redonda - RJ and the alternative of drying as a method for preserving the excess production, the objective of this study was to evaluate the drying process of green onions, considering the microbiological quality, and to develop the mathematical modeling of this process. Mathematical models to describe the drying of agricultural products were used to predict the phenomenon. The modified Page equation gave the best fit to the data. Microbiological quality was evaluated using the analysis of aerobic mesophilic bacteria, molds and yeasts. Dehydration at 60 ºC was the most indicated for green onions, with assured microbiological quality.摘要：大葱（Allium fistulosum L.）在巴西作为调味蔬菜被广泛消费与贸易。鉴于里约热内卢州沃尔塔雷东达（Volta Redonda - RJ）地区大葱产量较高，且干燥法可作为过剩产量的保鲜途径，本研究旨在评估大葱的干燥工艺（同时考量其微生物品质），并针对该工艺建立数学模型。本研究采用描述农产品干燥过程的数学模型对该干燥现象进行预测，其中修正帕奇（Page）方程对实验数据的拟合效果最优。研究通过需氧嗜温菌、霉菌及酵母菌的计数分析对样品的微生物品质进行评估，结果显示60℃下的干燥工艺最适用于大葱，且可保证其微生物品质合格。