Physico-chemical stability of honey-sweetened (Apis mellifera L.) yoghurt

Abstract Yogurt is obtained from milk fermentation through the action of specific lactic acid bacteria, and can be added with ingredients with functional properties, in order to add nutritional, sensory value and attractiveness to consumers. The objective of this research was to develop yoghurt sweetened with bee honey Apis mellifera L. and to monitor the physico-chemical stability during storage under refrigeration. Thus, six yoghurt formulations were added with 5% inulin and different honey concentrations (0, 4, 6, 8, 10 and 12%). The physicochemical stability behavior (total dry extract, ashes, pH and total titratable acidity - expressed in g of lactic acid) was evaluated during 35 days of storage at times 0, 7, 14, 21, 28 and 35 days. For this experiment was set up a completely randomized design in factorial scheme, being 6 treatments and 6 storage periods. Data were analyzed by analysis of variance and comparison of means by Tukey test at 5% significance. It was observed that the addition of honey in yoghurt promoted a significant increase (p <0.05) in the values of total dry extract and total titratable acidity, associated with reduction in ash values and pH. The yogurts met the standards of identity and quality recommended by the legislation and during storage underwent significant changes in all parameters influenced mainly by the honey concentration factor than storage time.

摘要：酸奶是通过特定乳酸菌（lactic acid bacteria）发酵牛乳制得，可添加具有功能特性的配料，以提升其营养价值、感官品质与消费者吸引力。本研究旨在开发添加西方蜜蜂（Apis mellifera L.）蜂蜜的酸奶，并监测其冷藏储存过程中的理化稳定性（physico-chemical stability）。为此，本研究设置6组酸奶配方，均添加5%菊糖（inulin），并搭配不同浓度的蜂蜜（0、4、6、8、10及12%）。在35天的储存周期内，分别于第0、7、14、21、28及35天对其理化稳定性指标进行评估，包括总干提取物（total dry extract）、灰分、pH值及总滴定酸度（以乳酸克数表示）。本实验采用完全随机因子设计，设置6个处理组与6个储存时间点。数据采用方差分析（analysis of variance）及Tukey检验（Tukey test）进行均值多重比较，显著性水平设定为5%。结果表明，在酸奶中添加蜂蜜可显著提升总干提取物与总滴定酸度（p<0.05），同时降低灰分含量与pH值。所制备的酸奶符合相关法规规定的产品身份与质量标准，且储存过程中各项指标均发生显著变化，其中蜂蜜浓度因素对指标的影响程度大于储存时间。