Low storage temperature maintains the quality, antioxidant activity, and nutraceutical properties of edible flowers and their anti-inflammatory effects on RAW 264.7 cells

Abstract

Edible flowers are increasingly used as functional foods that enhance human health by providing antioxidant and antiaging benefits, scavenging free radicals, and aiding in the prevention and care of cardiovascular diseases and cancer. However, the rapid loss of quality after harvesting, which reduces the aesthetic value, shelf life, and marketability of flowers, is a major research issue compared to their nutraceutical value. Therefore, this study investigated the changes in the quality, phytochemical properties, antioxidant activity, nutraceutical efficacy, and anti-inflammatory effects on RAW 264.7 cells of ten edible flowers after being harvested, packed in waterproof paper trays, covered with a transparent plastic lid, and stored at 10 °C and 21 °C for 6 days. Low storage temperature significantly delayed this deterioration while maintaining the antioxidant capacities and nutraceutical properties of flowers, whereas storage at 21 °C decreased these properties in some flowers. The result revealed that total phenolic content of C. pulcherrima (pink and orange) expressed higher to 1.22 and 1.20 mg/g FW, respectively, than other edible flowers. Also, the antioxidant capacity of C. pulcherrima orange flowers was effective against DPPH which initial value was 1632.89 μmol TE/g, while that of FRAP, ABTS, and ORAC were found in C. indicum showing 2364.20, 1974.87 and 5807.70 μmol TE/g, respectively. Compared with other flower extracts, C. pulcherrima and A. leptopus ‘Alba’ had high acetylcholinesterase activity of approximately 0.01–0.06 mg/mL and strong inhibition level of tyrosinase 0.16–0.22 mg/mL, while ACE inhibition was undetectable in all investigated edible flowers. However, flowers of C. pulcherrima (yellow) showed 100 % decay at 21 °C on day 3 of storage. Moreover, the inflammatory and anti-inflammatory effects of MeOH extracts (0–5 mg/mL, at the zero time) were also explored in RAW 264.7 cells. Almost all flowers modulated inflammation; A. goyazensis effectively inhibited NO generation and is therefore a candidate functional food.