Alteration on phenolic acids and the appearance of lotus (Nelumbo nucifera Gaertn) seeds dealt with antistaling agents during storage

This study evaluated the preservation effectiveness of selected antistaling agents on lotus seeds (Nelumbo nucifera Gaertn) status and the alteration of phenolic acids during their storage. Ascorbic acid (AA), benzoic acid (BA), sodium hydrogen sulfite (SHS), BA+ AA and SHS+ AA were identified as effective to keep lotus seeds fresh with the order of SHS+ AA > BA+ AA > AA > SHS > BA in terms of general performance on not-browning degree, microorganism contamination status, sensory evaluation, and the protection of polyphenols against being oxidized. The polyphenols determined by HPLC and HPLC-MS in lotus seeds were mainly gallic, chlorogenic, gentisic, caffeic, cinnamic, p-coumaric, ferulic, rosmarinic, and salicylic acids. Chlorogenic, gentisic, and caffeic acids were the main phenolic acids correlated with oxidative browning. SHS+ AA was found on inhibiting chlorogenic acid oxidized (p < 0.05) as well as SHS or AA did. BA+ AA also had protective effect on all these three phenolics. The increment of gallic, caffeic, chlorogenic, and p-coumaric acids at the beginning of storage, which was from the hydrolyzation of glycosides promoted by BA, had accordance with the deteriorate sensory of lotus seeds and led to worse anti-browning effect. Gallic acid was found to be relevant to the degree of microorganism contamination. The stronger antibacterial capacity antistaling agents had, the later regeneration of gallic acid appeared. In conclusion, the selected antistaling agents had different preservation effectiveness, which would synchronously indicate alteration of relevant phenolic acids profiles of lotus seed during storage.