The purpose of this research is to distinguish the quantitative determination of phytochemicals in various agricultural products and to optimize an HPLC method for the determination of lycopene, lutein, α-carotene, β-carotene, and cryptoxanthin. Among the different conditions studied, the most suitable ones for our samples were the extraction with hexane/acetone/ethanol (50:25:25, v/v/v), dissolution of the dry extract in tetrahydrofuran/acetonitrile/methanol (15:30:55, v/v/v), injection on a C18 column with methanol/acetonitrile (90:10, v/v) + triethylamine 9 μM as mobile phase, and λdetection=475 nm. The mean percent recovery for the HPLC method were 120.7±4.1% (lycopene), 89.2±3.5% (lutein), 91.2±2.9% (α-carotene), 99.1±4.4% (β-carotene), and 100.0±5.3% (cryptoxanthin). The contents of lutein in the agricultural products were spinach, kiwi, tomato, blueberry, melon, respectively. However, the lycopene contents were the highest in the Black tomato (56.66±7.48 mg/kg) and Jangseong tomato (50.28±5.42 mg/kg). The concentration of β-carotene in all of the agricultural products ranged from 0.07 mg/kg to 65.03 mg/kg. The quercetin content of the agricultural products increased in the order of blueberry (986.57∼1,054.06 mg/100 g), kiwi (44.96∼55.09 mg/100 g), hallabong (31.92∼35.60 mg/100 g), and tomato (26.38∼34.94 mg/100 g). The highest kaempferol content was found in the blueberry (47.79∼76.15 mg/100 g) with results in all of the tested samples varying between 6.54∼48.11 mg/100 g. The total polyphenol contents of the various agricultural products increased in the blueberry (213.60∼229.96 mg/100 g), spinach (112.50∼141.67 mg/100 g) and kiwi (46.49∼70.44 mg/100 g). The total flavonoid content was the highest in both blueberry and spinach. Vitamin C content was detected in kiwi > hallabong > tomato > blueberry, respectively. The total anthocyanin contents (TAC) was detected in the Damyang blueberry and the imported blueberry.

In recent years, polyphenol-rich herbs, fruits and processed foods, which are made of plant origin, have attracted much attention due to their potential health benefits. Pomegranate (Punica granatum L.) is an important source of bioactive compounds and has been used to treat diseases because of its medicinal properties. This research was focused on characterizing Korea’s national cultivar and a similar product from California, USA. To evaluate their bioactive compounds and pharmacological activities, their anti-oxidation and cancer inhibition properties, as well as their organic acid and free sugar contents, were investigated. The national cultivar had low total sugar and high organic acid contents, contrary to the imported product. The results showed that the peel of national cultivar had high polyphenol and ellagic acid contents compared to imported product. The free radical scavenging capacity was evaluated via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and its positive correlation with the total polyphenol contents was found. The anti-cancer activity of methanol extracts revealed growth inhibition against the prostate cancer cell. These results signify that while pomegranate, national cultivar, is more sour than the imported product, its health benefits could be excellent. Also, the polyphenol compound content of the non-edible part (such as the peel and the seed) was higher than that of the juice. Thus, it is suggested that the byproduct of the juice extraction could be potentially used in other fields such as medicine or dietary agents.