Department of Agricultural and Food Sciences, University of Bologna, Piazza Goidanich 60, 47521 Cesena, Italy.
Interdepartmental Centre for Agri-Food Industrial Research, University of Bologna, Via Quinto Bucci 336, 47521 Cesena, Italy.
Molecules. 2020 Jul 21;25(14):3309. doi: 10.3390/molecules25143309.
Kiwifruit is an excellent source of vitamin C and other bioactive compounds, which contribute to its high antioxidant activity. However, the fruits with small size and low weight are considered waste and are unprofitable; therefore, the production of healthy kiwifruit-based dried snacks, which contain a lot of health-beneficial ingredients, could be a viable alternative for their use. The aim of this study was to develop formulations and methods to produce attractive and nutritionally valuable dried snacks based on yellow kiwifruit. Three different puree formulations (kiwifruit; fennel; and strawberry, lemon, or spinach) with or without addition of sugar were subjected to two drying methods: freeze-drying (fruit bars) and conventional hot air drying (fruit leathers). The obtained products were analysed for their content of total polyphenols (TPs), flavonoids, and vitamin C, as well as their antioxidant activity. The results showed that snacks prepared by freeze-drying (fruit bars) presented higher TP, vitamin C, and flavonoids content than those prepared by convective drying; however, the antioxidant activity did not always follow this trend. The amount of bioactive compounds depended on the formulation used for the preparation of snacks. The effect of the sugar addition seems to be strictly related to the mix used and specific bioactive compound investigated.
奇异果是维生素 C 和其他生物活性化合物的极佳来源，这些化合物有助于其具有高抗氧化活性。然而，那些体积小、重量轻的奇异果通常被视为废物，没有经济价值；因此，生产富含大量有益健康成分的健康奇异果干零食，可能是一种可行的利用方式。本研究旨在开发配方和方法，以生产基于黄奇异果的有吸引力和有营养价值的干零食。三种不同的果泥配方（奇异果、茴香和草莓、柠檬或菠菜），无论是否添加糖，都经过两种干燥方法处理：冷冻干燥（水果棒）和传统的热空气干燥（水果皮）。对所得产品进行总多酚（TPs）、类黄酮和维生素 C 含量以及抗氧化活性分析。结果表明，通过冷冻干燥（水果棒）制备的零食的 TP、维生素 C 和类黄酮含量高于通过对流干燥制备的零食；然而，抗氧化活性并不总是遵循这一趋势。生物活性化合物的含量取决于用于制备零食的配方。糖的添加效果似乎与所用的混合物和特定的生物活性化合物密切相关。
