Shonai persimmon is the common name for persimmons cultivated in the Shonai area of Yamagata Prefecture, Japan. They are also known as the cultivar Hiratanenashi (Diospyros kaki L.) and are one of the region’s most popular fruits. The systolic blood pressure of spontaneously hypertensive rats (SHR) fed basal diets supplemented with either persimmon or an extract of soluble tannins decreased when compared to SHR fed the basal diet, and increased after switching to the basal diet alone. Two persimmon food materials, persimmon paste and persimmon vinegar, that can be used for processing food containing persimmon were developed. Persimmon paste lacking astringency was developed by the addition of proteins such as silk fibroin (silk protein powder) to the persimmon homogenate. Persimmon paste processed from persimmon with its peel contained most of the original flavor and bioactive components of persimmon. Persimmon vinegar, referred to as Shonai persimmon vinegar, was produced using various microbes isolated from a vinegar brewery over an extended period (about two years), resulting in its characteristic taste and flavor, as well as its high amino acids content. Persimmon paste and persimmon vinegar are now used for the development of various foods and beverages.
Antioxidant micronutrients such as vitamins and carotenoids exist in abundance in fruits and vegetables and are known to contribute to the body’s defense against reactive oxygen species. Numerous recent epidemiologic studies have demonstrated that a high dietary consumption of fruits and vegetables rich in carotenoids or producing high serum carotenoid concentrations results in a decreased risk for certain cancers, diabetes, and cardiovascular disease. These epidemiologic studies have suggested that antioxidant carotenoids exert a protective effect against several lifestyle-related diseases. Beta-cryptoxanthin is a carotenoid pigment particularly found in Japanese mandarin (Citrus unshiu Marc.) fruit, which is heavily produced in Japan. Our nutritional epidemiologic survey, the Mikkabi Study, utilized data derived from health examinations involving inhabitants of the town of Mikkabi in Shizuoka, Japan. In this survey, we measured serum beta-cryptoxanthin as a specific bio-marker to estimate the consumption of Japanese mandarin fruit. The cross-sectional analyses of the Mikkabi Study indicated inverse associations between serum β-cryptoxanthin and the risk for atherosclerosis, insulin resistance, liver dysfunction, metabolic syndrome, low bone mineral density and oxidative stress. In this chapter, recent epidemiologic studies of the association between serum beta-cryptoxanthin and the risk for several lifestyle-related diseases are reviewed.
In Japan, due to a decrease in Satsuma mandarin production and an increase in the number of citrus varieties produced, citrus extraction factories are forcing many products to be grown in small lots and other such facilities for mass production. In the juice industry, many factories are inefficiently operated. Therefore, the practical use of a juice by-product, effective use of small quantities of juice from various kinds of citrus, and the development of products that focuses on fruit functionality in regards to human health are required to improve the profitability of such factories.