Low-Temperature Effects on the Growth and Phytochemical Properties of Wheat Sprouts

Sprouting is associated with nutritional value, as microgreens stimulate the accumulation of health-promoting phytochemicals. The purpose of this study was to examine the growth rates and cell protection activity against oxidative stress in sprouts of seven wheat varieties, and to investigate the influence of low temperatures on their phytochemical characteristics. Among the seven wheat varieties (five Korean varieties, Australian standard white, and Chinese wild-type wheat germplasm), purple wheat (Ariheuk) had the fastest growth pattern for 8 days and provided the most protection to skin cells and hepatocytes against oxidative stress. Following low-temperature treatment (<4 °C) for 1–4 days, cold exposure had a similar effect on the growth of purple wheat sprouts during an 8-day period. However, growth was negatively affected by exposure to low temperatures for more than 5 days. Purple wheat sprouts treated with low temperatures for 4 days had considerably higher total polyphenol and total flavonoid contents, as well as a higher antioxidant capacity than untreated wheat sprouts. These findings suggest that low-temperature treatment promotes the expression of phytochemicals in purple wheat sprouts. Thus, purple wheat sprouts are considered a high-value crop that could be used as a functional food material.