In this study, we investigated the nutritional composition including proximate, amino acid, vitamin, minerals, and the antioxidant activity of green tea (Camellia sinensis) pollen grains collected by Apis mellifera bees, for use as a health food. The crude protein and fat content was estimated at 26.14% and 3.49%, respectively. Eighteen amino acids were identified in green tea pollen, including 8 essential amino acids and 10 non-essential amino acids. The predominant amino acids were glutamic acid, proline and aspartic acid accounting for about 33.3% of total free amino acids. The concentration of vitamin C was the highest value of 35.7%, followed by B3 and B2 among the detected vitamins. The predominant minerals were potassium (790.32 mg/100g), followed by phosphorus (707.52 mg/100g) and sulfur (302.67 mg/100g), whereas copper, zinc and sodium were detected as minor elements. The antioxidant activity and phenolic content accounted for 33.8% at 500 μg/mL extract and 2.55 μg/mg, respectively.

Honey production from approximately 1.7 million colonies owned by around 21 thousand beekeepers was almost 36 thousand M/T in Korea. Pollen has used as a food and medicine from before the Joseon Dynasty period in Korea. Pollen grains such as acorn (Quercus acutissima), actinidia (Actinidia arguta) and green tea (Camellia sinensis) are popular in the markets in Korea. But stiff pollen wall hindered dissolution of polysaccharides and lowered extraction efficiency. In the present study, we measured the antioxidant activity and the total polyphenol content from the pulverized and lyophilized green tea pollen grains inoculated with 6 kinds of fungi to confirm the husk removal effect. The total polyphenol content of green tea pollens was highest in lyophilized pollen medium inoculated with Armillaria mellea, and was lowest in pollen inoculated with Lentinula edodes. Total polyphenol content of the lyophilized pollen was higher than that of the refined pollen and the pulverized pollen in green tea pollen germinated with A. mellea. The total polyphenol content of the lyophilized green tea pollens germinated with A. mellea was 1.4-fold higher than that extracted with water. Measurement of antioxidant activity using the DPPH free radical scavenging method showed that the lyophilized green tea pollen grains germinated with A. mellea had the highest and that germinated with L. edodes was lowest in antioxidant activities. The lyophilized green tea pollen grains germinated with A. mellea was 2 to 4 times higher than that extracted with water in the antioxidant activity of DPPH free radical scavenging. Many germinated cells were formed around pore of green tea pollen inoculated with L. edodes, while those were formed at the end of hyphae derived from green tea pollen grains inoculated with A. mellea.