文章基本信息

标题：Convective Drying of Fresh and Frozen Raspberries and Change of Their Physical and Nutritive Properties
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作者：Zoran Stamenković ; Ivan Pavkov ; Milivoj Radojčin 等
期刊名称：Foods
电子版ISSN：2304-8158
出版年度：2019
卷号：8
期号：7
页码：1-14
DOI：10.3390/foods8070251
出版社：MDPI Publishing
摘要：Raspberries are one of Serbia’s best-known and most widely exported fruits. Due to market fluctuation, producers are looking for ways to preserve this fresh product. Drying is a widely accepted method for preserving berries, as is the case with freeze-drying. Hence, the aim was to evaluate convective drying as an alternative to freeze-drying due to better accessibility, simplicity, and cost-effectiveness of Polana raspberries and compare it to a freeze-drying. Three factors were in experimental design: air temperature (60, 70, and 80 °C), air velocity (0,5 and 1,5 m · s−1), and state of a product (fresh and frozen). Success of drying was evaluated with several quality criteria: shrinkage (change of volume), color change, shape, content of L-ascorbic acid, total phenolic content, flavonoid content, anthocyanin content, and antioxidant activity. A considerable influence of convective drying on color changes was not observed, as ΔE was low for all samples. It was obvious that fresh raspberries had less physical changes than frozen ones. On average, convective drying reduced L–ascorbic acid content by 80.00–99.99%, but less than 60% for other biologically active compounds as compared to fresh raspberries. Convective dried Polana raspberry may be considered as a viable replacement for freeze-dried raspberries.
关键词：raspberry; convective drying; freeze-drying; bioactive compounds; shrinkage; color change raspberry ; convective drying ; freeze-drying ; bioactive compounds ; shrinkage ; color change