Ikegaya Atsushi, Toyoizumi Tomoyasu, Ohba Seiji, Nakajima Teruko, Kawata Tomoaki, Ito Seiko, Arai Eiko
Shizuoka Prefectural Research Institute of Agriculture and Forestry Iwata Japan.
Graduate School of Integrated Pharmaceutical and Nutritional Sciences University of Shizuoka Shizuoka Japan.
Food Sci Nutr. 2019 Jun 13;7(7):2419-2426. doi: 10.1002/fsn3.1109. eCollection 2019 Jul.
The concentrations of sugars and organic acids as well as the total soluble solid (TSS) in different parts of the strawberry fruit were characterized. The data were used to create simulated fruit juice jellies, in order to clarify how the sugar and organic acid levels affect the taste. Such an approach eliminates the influence of external factors such as size, color, and texture when using real fruits in sensory evaluations. Further, the use of a jelly allowed us to simulate the concentration differences between various parts of the fruit. In the strawberry fruit, the sugar content is higher in the apex than in the peduncle; however, the level of organic acids is the same throughout. It was revealed that the sweetness and sourness in the apex and peduncle could be sufficiently recognized by humans as tastes. Also, a layered jelly sample replicating the sugar and acid distribution in real strawberry was perceived as less sweet and more sour, compared to a homogeneous one with the same overall composition. The likely reason is that the sourness in the peduncle is accentuated by the low TSS level, which decreases the TSS/total organic acid ratio that affects the sweetness/sour perceptions. Based on these results, factors for the appropriate sensory evaluation of fresh fruits in general were considered. Specifically, the distribution of sugars and organic acids in the fruit should be analyzed first, and bite-sized parts with concentrations close to the average provide the most accurate evaluation results.
对草莓果实不同部位的糖、有机酸浓度以及总可溶性固形物（TSS）进行了表征。这些数据用于制作模拟果汁果冻，以阐明糖和有机酸水平如何影响口感。这种方法消除了在感官评价中使用真实水果时大小、颜色和质地等外部因素的影响。此外，使用果冻使我们能够模拟果实不同部位之间的浓度差异。在草莓果实中，顶部的糖含量高于果梗；然而，有机酸水平在整个果实中是相同的。结果表明，人类能够充分识别顶部和果梗的甜味和酸味。此外，与具有相同总体组成的均匀果冻相比，复制真实草莓中糖和酸分布的分层果冻样品被认为甜度较低、酸度较高。可能的原因是果梗中的酸味因低TSS水平而加剧，这降低了影响甜味/酸味感知的TSS/总有机酸比率。基于这些结果，考虑了一般新鲜水果进行适当感官评价的因素。具体而言，应首先分析果实中糖和有机酸的分布，浓度接近平均值的一口大小的部分提供最准确的评价结果。
