Comprehensive changes in volatile/nonvolatile compounds and flavor and physicochemical characteristics inAngelica gigasNakai roots by thermal processing

Abstract

This study investigated the changes of physicochemical and flavor characteristics of Angelica gigas Nakai roots during roasting. Glutamic acid and arginine were higher in constituent amino acids. In the taste value, glutamic acid was highest in constituent and free amino acids. Total phenol contents were highest in 0 min and lowest in 3 min. Hundred twenty‐six volatile compounds were detected by GC/MS during roasting. α‐pinene, eudesmol, nonane, and limonene were detected as major volatile compounds. For antioxidant ability, 1,1‐diphenyl‐2‐picrylhydrazyl did not change during roasting, and 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulphonic acid showed the highest value in 3 min. Browning intensity showed a slight decrease over time. In Electronic nose, fragrance increased by roasting, and strength, NH3, and H2S decreased significantly. In Electronic tongue, sweetness, bitterness, and umami taste increased by roasting, and this was related to amino acid composition. The results provide basic data on the physicochemical and flavor characteristics of A. gigas Nakai according to the roasting process. Practical applications Angelica gigas Nakai has been known as a medicinal herb in Asian countries and usually consumed in powder, tea, and snacks. In order to produce the powder, tea, or snacks with A. gigas Nakai, thermal treatment is an essential and critical process. Despite that existing studies reported many physiological benefits and functional properties of A. gigas Nakai, studies have rarely discovered how the nutritional properties and volatile compounds of A. gigas Nakai alter when it undergoes thermal treatment. Therefore, this study will be utilized as basic data to optimize the thermal processing conditions (e.g., roasting time) for the production of food products with A. gigas Nakai such as tea and snacks. This study further provides objective chemical measures of sensory profiles of A. gigas Nakai using electronic tongue and electronic nose during the thermal processing.

Platycodon grandiflorumroots: A comprehensive study on odor/aroma and chemical properties during roasting

“…In addition, sweet taste increased over time, which coincides with the increased content of glycine. Recent studies reported that Angelica gigas Nakai, Perilla frutescens Britton, and Cynanchi wilfordii Radix showed an increase in umami and bitter tastes with roasting, which is in agreement with the result of this study, whereas sweet and sour tastes showed some variations (Kim et al, 2018; Kim et al., 2019; Lee et al., 2019). Fortunately, the taste results mildly coincide with the result of free amino acid patterns in this study.…”

“…Kim et al. (2019) also found that arginine was the most abundant free amino acid and significantly decreased with roasting of Angelica gigas Nakai at 180°C for 0–5 min, which is in consistent with the result of this study ( p < .05). γ‐aminobutyric acid (GABA), a relatively common amino acid found in medicinal herbs such as Angelica gigas Nakai, Perilla frutescens Britton, and Cynanchi wilfordii Radix, was also observed in the present study (Kim et al, 2018; Kim et al., 2019; Lee et al., 2019).…”

“…Roasting also generates reductones with high reducing power in phenolic compounds, presumably leading to an increase of total phenolic content (Kim et al, 2018; Yoon et al., 2005). In comparison to the recent studies by our research group, Platycodon grandiflorum , 0.24 ± 0.01 mg/ml, possessed higher total phenolic content than Perilla frutescens Britton, 0.11 ± 0.01 mg/ml, and lower than Angelica gigas Nakai, 42.52 ± 1.08 mg/ml (Kim et al., 2019; Lee et al., 2019).…”

“…This result was in agreement with recent studies by our research group in that glutamic acid was the most prevalent amino acid in both Angelica gigas Nakai and Perilla frutescens Britton var. acuta Kudo during roasting process (Kim et al., 2019; Lee et al., 2019). Glutamic acid only has sour taste, whereas monosodium glutamate, a combination with sodium, creates savory taste that is also known as umami taste.…”

“…Chemical components relevant to sensory characteristics in Platycodon grandiflorum during the roasting process were analyzed and the results are depicted in Figure 1. Electronic tongue module provides an objective analysis via relative comparisons of the tastes, and many studies have been utilized electronic tongue module in taste description of medicinal herbs (Kim et al, 2018; Kim et al., 2019; Lee et al., 2019). Umami taste and bitter taste substantially increased under the roasting conditions.…”