Functional Evaluation of Loquat (Eriobotrya japonica Lindl.) Flower Water Extracts and Its Potential Use in Tea

Abstract

In traditional Chinese medicine, loquat leaves have been commonly used to relieve cough and expectoration. Recently, it has been proved that loquat fruit, kernels, leaves, and flowers can be used as herbal medicines to prevent cardiovascular diseases, cancer, inflammation, and other chronic diseases. This study extracted the loquat flowers (LF) at different temperatures and times to prepare the LF water extract (LFWE). In addition, the antioxidant activity and anti-inflammatory performance of LF extract were evaluated. Moreover, the potential of developing sugar-free LF tea was evaluated. The results showed that the LFWE with a temperature above 80°C and heating for 60 min had a higher content of bioactive compounds, which was significantly different compared with other extraction conditions ($p<0.05$); antioxidant ability trial results showed the performance of the same trend ($p<0.05$). However, LFWE was not toxic to cell viability, and the amount of PGE2 production was significantly lower than that of the induced group ($p<0.05$), thus considerably inhibiting the production of PGE2, a marker of inflammation and effectively reducing inflammatory responses. The LF tea prepared at 90°C for different times (15, 30, 45, and 60 min) showed a significant decrease in $L^{\ast }$ value as the extraction time increased significantly to darkness. In addition, the sensory evaluation results revealed that the overall acceptability scores of LF tea extracted for 45 min were the highest, and there was a significant difference ($p<0.05$). Hence, LF is one of the good products for functional beverages and foods.