Production and storage stability of acerola flour dehydrated at different temperatures

Abstract The objective of this work was to identify the best dehydration temperature for the production of high quality acerola flour and to provide stability of the physicochemical parameters during storage. ‘Flor Branca’ acerolas were harvested at the red ripe stage in a commercial orchard in the São Francisco Valley, Petrolina, PE, Brazil. Fruits with or without seeds were dried at 60, 70 and 80°C in a forced air circulating oven. The dried fruits were then ground to obtain the flour, which was stored at room temperature in hermetically sealed polyethylene bags. The fresh fruit pulp was evaluated for its pH value, soluble solids (SS), titratable acidity (TA), ascorbic acid (AA) and moisture contents. The acerola flour was analysed every 15 days for 75 days for pH, SS, AT, AA and colour. For all the drying temperatures, the pH and SS showed similar levels, ranging from 3.5 to 4.2 and 6.3 to 11.7, respectively. The TA increased during storage for all the drying temperatures, ranging from 5 to 10%. The AA losses were 76.2 and 80%, 23.9 and 55%, and 37.9 and 65% for flours obtained from fruits with and without seeds, dehydrated at 60, 70 and 80°C, respectively. According to the results, the best drying temperature was 70°C, which resulted in high flour quality and physicochemical stability during the 75 days of storage.

摘要 本研究旨在确定制备高品质针叶樱桃粉的最优脱水温度，并保障其贮藏过程中理化参数的稳定性。实验于巴西佩特罗利纳市（伯南布哥州）圣弗朗西斯科谷的商业果园中，采收红熟期的‘Flor Branca’针叶樱桃果实。将带籽与去籽的果实分别置于鼓风循环烘箱中，以60℃、70℃、80℃三种温度进行干燥。干燥完成后将果实磨粉，随后将所得针叶樱桃粉置于密封聚乙烯袋中，于室温下贮藏。对新鲜果肉的pH值、可溶性固形物（soluble solids, SS）、可滴定酸度（titratable acidity, TA）、抗坏血酸（ascorbic acid, AA）及水分含量进行了测定。在75天的贮藏期内，每隔15天对针叶樱桃粉的pH值、SS、TA、AA及色泽进行检测分析。在所有干燥温度条件下，pH值与可溶性固形物含量均维持在相近水平，pH值范围为3.5~4.2，可溶性固形物含量范围为6.3~11.7。在所有干燥温度组中，贮藏期内可滴定酸度均有所上升，增幅为5%~10%。分别以60℃、70℃、80℃脱水制备的带籽与去籽樱桃粉，其抗坏血酸损失率依次为76.2%与80%、23.9%与55%、37.9%与65%。综合实验结果可知，70℃为最优干燥温度，该条件下制备的针叶樱桃粉品质优异，且在75天贮藏期内理化性质保持稳定。