Effect of drying and harvest time on the physicochemical properties of the most common Korean persimmon leaves

Abstract

long been associated with the prevention of diseases such as scurvy. Ascorbic acid is easily degraded, however, as a result of several factors such as temperature, pH, light intensity, oxygen, enzymes, metallic catalyzers, relative humidity, physical damage, frost damage, adverse handling, and storage conditions (3,4). Moreover, it is important to recognize the seasonal changes in the mineral contents of the leaves and identify the optimum harvesting time. Leaf-nutrient analysis plays an important role in evaluating future fertilization requirements (5) and also plays a significant part in the growth and development of plants and fruit quality. Thus, it is important to be aware of the fluctuations in the mineral contents of persimmon leaves in order to determine the optimum harvesting time. Not least, macro-and micro-nutrients play an active role in the prevention and treatment of atherosclerosis as well as coronary heart diseases (6,7). The drying method can affect the quantity and quality of the final product. Drying is necessary to ensure the physical, chemical, and microbiological stability of the harvested persimmon leaves. Any drying process should be capable Effect of drying and harvest time on the physicochemical properties of the most common Korean persimmon leaves

Persimmon Leaves: Nutritional, Pharmaceutical, and Industrial Potential—A Review

“…PL are commonly used in a dried form to make functional tea. The moisture content of fresh persimmon is around 75–80%, while the powder obtained from dried leaves contains 10 and 4% moisture when dried using hot-air and freeze-drying, respectively [ 1 ]. The major pigments in PL are chlorophylls, xanthophylls, anthocyanins, and carotenes, which are responsible for changing colors throughout the growing season.…”

“…The major pigments in PL are chlorophylls, xanthophylls, anthocyanins, and carotenes, which are responsible for changing colors throughout the growing season. Hossain et al [ 1 ] investigated the Hunter color values of the most common PL grown in Korea and found that L* (lightness), a* (yellowness), and b* (redness) values were 57.92–62.14, 1.42–2.31, and 15.96–20.13, respectively, for the freeze-dried leaves. In contrast, Chung et al [ 19 ] found that the L*, a*, and b* values were 43.55, −15.05, and 26.83, respectively, for fresh PL.…”

“…Contrarily, the contents of chlorophyll a and b of the Korean PL tea were 0.22 and 0.52 mg/g, respectively [ 23 ]. Furthermore, Hassan et al [ 24 ] reported that freeze-dried PL ( D. lotus ) harvested from Korea contained 12.6–14.6 mg/g of vitamin C. Similarly, the content of vitamin C in freeze-dried PL ( D. Kaki ) obtained from various regions of Korea during the flowering stage was 7.53–14.87 mg/g [ 1 ]. It was also reported that the PL were a good source of minerals, mainly K (538.24–971.58 mg/100 g), Ca (255.7–591.25 mg/100 g), Mg (69.07–153.33 mg/100 g), Mn (4.78–36.49 mg/100 g), Fe (3.44–13.77), Na (7.05–12.63), Cu (1.54–5.8), and Zn (0.76–2.34).…”

“…Concentrations of most of the elements were lower in the early growing season, followed by increasing mid-season, and started declining again at the end of the season. In another study, Hossain et al [ 1 ] suggested that the concentration of Ca, Mg, K, and Mn increased from May to June but decreased for Fe, Na, Cu, and Zn in PL collected from Korea. Moreover, PL harvested in May (flowering stage) had a higher content of vitamin C and moisture than those harvested in late June (fruiting stage).…”

“…Persimmon fruit is eaten fresh or dried (primarily astringent type), while leaves are well-known as functional tea in East Asian countries. In Japanese culture, PL are infused with hot water and consumed as functional tea (“kakinoha-cha”), which is traditionally known for curing paralysis, burns, and frostbite, as well as to stopping bleeding [ 1 , 2 ]. Persimmon trees are deciduous, hence their leaves are of interest as functional food ingredients, nutraceuticals, and pharmaceuticals.…”