Phenolic profile, free amino acids composition and antioxidant potential of dried longan fermented by lactic acid bacteria

• Published in: Journal of food science and technology Vol. 55; no. 12; pp. 4782 - 4791
• Main Authors: Khan, Sher Ali, Liu, Lei, Lai, Ting, Zhang, Ruifen, Wei, Zhencheng, Xiao, Juan, Deng, Yuanyuan, Zhang, Mingwei
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 01.12.2018; Springer Nature B.V
• Subjects: Amino acid composition; Amino acids; Antioxidants; Aspartic acid; Bacteria; Bitter taste; Butyric acid; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Composition; Coumaric acid; Cysteine; Fermentation; Food Science; Fruits; Gallic acid; High-performance liquid chromatography; Lactic acid; Lactic acid bacteria; Lactobacillus plantarum; Leucine; Leuconostoc mesenteroides; Liquid chromatography; Longan; Nutrition; Organic acids; Original; Original Article; p-Coumaric acid; Phenols; Phenylalanine; Pulp; Reactive oxygen species; Studies; Taurine; Thiazoline; Tyrosine; Vanillic acid; Free amino acid; Longan; Lactic fermentation; Antioxidant activity; Organic acid; Phenolic composition
• ISSN: 0022-1155; 0975-8402
• DOI: 10.1007/s13197-018-3411-8

In this study, dried longan pulp (DLP) was subjected to fermentation using selected strains of lactic acid bacteria ( Lactobacillus plantarum subsp. Plantarum and Leuconostoc mesenteroides ). We then studied changes in the free and bound phytochemical profile, antioxidant activity, free amino acid, and organic acid composition. Fermentation exhibited a 17.4% and 5.7% increase in the amount of free and total phenolic contents of DLP. Phenolic composition determined by HPLC revealed significant changes due to fermentation that were primarily in the contents of gallic acid, vanillic acid, 4-methylcatechol and p -coumaric acid, resulting in a 37.9% and 25.7% increase in free gallic acid and 4-methylcatechol, respectively. Fermentation was also found to enhance the ferric reducing antioxidant power of both free and total and the oxygen radical absorbance capacity of free phenolic fraction by 18.3%, 11.8%, and 37.4%, respectively. In addition, fermentation was observed to reduce the contents of free amino acids with bitter taste (phenylalanine, tyrosine and leucine), and increase amino acids (taurine, aspartic acid, cysteine, cysteine thiazoline and γ-amino-butyric acid) having antioxidant potential. Therefore, this study provides basis for the production of fermented longan-based functional products with improved antioxidant activity.