title: Evaluation of γ- aminobutyric acid, phytate and antioxidant activity of tempeh-like fermented oats (Avena sativa L.) prepared with different filamentous fungi.
abstract: Tempeh is a popular traditional fermented food in Asia. Many tempeh-like foods are made from cereal grains. However, the information of γ-aminobutyric acid (GABA) accumulation in those tempeh-like cereal grains during fermentation is lacking. Meanwhile, little information is available on the anti-nutrient contents and antioxidant activity of tempeh-like fermented oats. The aim of the present work was to study the changes of GABA, phytate, natural antioxidants and antioxidant activity of tempeh-like fermented oats. As fermentation time progressed, the GABA, total phenolics content (TPC) and flavonoids increased rapidly. The Aspergillus oryzae-fermented oats had the highest GABA, whereas Rhizopus oryzae-fermented oats had the highest TPC. Phytate, an anti-nutrient component, was dramatically reduced in the fermented oats, especially those by A. oryzae (reduced by about 63 %). The antioxidant activities of fermented oats were also significantly enhanced after 72 h fermentation (p < 0.05). This study demonstrated that oats fermented by generally recognized as safe (GRAS) fungi can be recommended as tempeh-like functional foods with higher GABA, more natural antioxidants and lower phytate compared with native oats.
authors.affiliation: College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China 100083.
authors.forename: Shengbao
authors.initials: S
authors.lastname: Cai
authors.affiliation: College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China 100083.
authors.forename: Fengyi
authors.initials: F
authors.lastname: Gao
authors.affiliation: College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China 100083.
authors.forename: Xudong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China 100083.
authors.forename: Ou
authors.initials: O
authors.lastname: Wang
authors.affiliation: College of Engineering, China Agricultural University, Beijing, People's Republic of China 100083.
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.affiliation: College of Engineering, China Agricultural University, Beijing, People's Republic of China 100083.
authors.forename: Songjie
authors.initials: S
authors.lastname: Zhu
authors.affiliation: College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China 100083.
authors.forename: Di
authors.initials: D
authors.lastname: Zhang
authors.affiliation: College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China 100083.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.affiliation: College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, People's Republic of China 100083.
authors.forename: Baoping
authors.initials: B
authors.lastname: Ji
keywords: Antioxidant activity; Filamentous fungi; Flavonoids; GABA; Phytate; TPC