Optimized Roasting Conditions of Germinated Wheat for a Novel Cereal Beverage and Its Sensory Properties.

Thinzar Aung,Mi Jeong Kim,Bo Ram Kim

doi:10.3390/foods11030481

Abstract

The objective of this study was to investigate the possibility of using germinated wheat as a nutritionally improved novel cereal beverage. To enhance the health-related functionality of a germinated wheat beverage (GWB), the roasting time and temperature of germinated wheat were optimized using a central composite design and response surface methodology. The optimum roasting conditions were determined as roasting temperature of 180 °C and roasting time of 44.56 min, resulting in maximum total flavonoid content (0.74 mg CE/g), total phenolic content (1.95 mg GE/g), 2,2-diphnyl-1-picrylhydrazyl (DPPH) radical scavenging activity (5.10 μM TE/g), Trolox equivalent antioxidant capacity (9.45 mM TE/g), and γ-aminobutyric acid content (2.25 mg/g). The germinated wheat roasted with optimum conditions was prepared in two types of GWB (hot and cold), and the sensory characteristics were tested by consumers (n = 102). The cold GWB showed relatively high preferences compared to hot GWB in appearance, odor, taste, and overall acceptabilities. In the intensity results of the sensory properties of GWB, the cold GWB tended to have stronger browning, grain odor, and nutty taste than the hot GWB. Conclusively, this study showed that optimizing the roasting conditions of germinated wheat could achieve desirable sensory properties and consumer acceptance while improving the health-related functionality of GWB.

Highlights

Wheat (Triticum aestivum L.) known as one of the world’s most important cereal crops, is widely utilized in the production of flour, malt, beer, and various end-uses such as bread, biscuits, noodle, pasta, and snacks [1,2]
Another study reported that germination can enhance the free and bound phenolic content, as well as increase antioxidant activity [5]
Gamma-Aminobutyric acid (GABA), catechin, gallic acid, 2,2-diphnyl1-picrylhydrazyl (DPPH), potassium persulfate, trichloroacetic acid, potassium persulfate, aluminium chloride, and sodium hypochlorite were purchased from Sigma-Aldrich

Summary

Introduction

Wheat (Triticum aestivum L.) known as one of the world’s most important cereal crops, is widely utilized in the production of flour, malt, beer, and various end-uses such as bread, biscuits, noodle, pasta, and snacks [1,2]. The enrichment of bioactive compounds in wheat-related products has become a major focus of food product development. Among the methods employed to fortify nutritional value, germination is one of the most promising ways to enhance bioactive compounds such as folate, γ-aminobutyric acid (GABA), tocopherols, vitamins, and flavonoids in cereal grains by activating related enzymes [3,4]. The germination process induces enzyme activation and antioxidant synthesis to protect the plant from oxidative damage [2]. Germination synchronously increases the levels of phenolic compounds such as p-coumaric, p-hydroxybenzoic, and syringic acids in Polish wheat [1]. Another study reported that germination can enhance the free and bound phenolic content, as well as increase antioxidant activity [5]

Objectives

Methods

Results