Comprehensive evaluation of physicochemical properties and antioxidant activity of B. subtilis‐fermented polished adlay subjected to different drying methods

Abstract

The physicochemical properties and antioxidant activity of B. subtilis‐fermented polished adlay (BPA) subjected to different drying methods (hot‐air drying, HAD; infrared‐radiation drying, IRD; vacuum drying, VD; microwave‐vacuum drying, MVD; and freeze‐vacuum drying, FVD) were evaluated in this study. Results showed FVD was ideal for maintaining the natural appearance and higher contents of proximate compositions, free fatty acids, tetramethylpyrazine (6.91 mg/g DW), coixol (0.62 mg/g DW), coixenolide (4.21% DW), coixan (35.10% DW), and triterpenoids (17.41 mg/g DW). The higher contents of total phenolics and flavonoids, stronger antioxidant activity, and higher color differences were observed in HAD and IRD samples. MVD displayed the shorter drying time, higher γ‐aminobutyric acid content, and higher retention ratios of tetramethylpyrazine (75.54%), coixol (87.10%), coixenolide (98.57%), and coixan (99.11%). Pearson's correlation coefficient exhibited that the positive correlation between the contents of phenolics and flavonoids and the antioxidant activities of all dried BPA samples was observed (R2 > 0.881, p < .05). Principal component analysis showed that the top three categories of comprehensive quality were FVD‐, MVD‐, and VD‐treated BPA samples. In conclusion, MVD should be a potential preservation method to obtain high‐quality dried BPA for short drying time and high comprehensive quality.

Impact of different drying methods on the drying time, energy, and quality of green peas

“…Bars with different letters differ significantly from each other at (p < .05) as determined by the LSD test changes (ΔE = 63.59) were obtained in the SD dryers. The lowest amount of changes in the freeze method indicates the better color preservation by this type of drying, because the sample is not exposed to heat for a long time and to the oxidation of the pigments and the color is better preserved (preventing from chlorophyll degradation)(Choo et al, 2020) Wen et al (2020). achieved similar results by comparing different drying methods (IR, MW, FD, HA, and vacuum).…”

“…As it can be seen there, the drying period for Also with the microwave, more heat was generated within the samples green pea, rapidly forming a vapor pressure. And then, a vapor pressure gradient was created between the samples and surrounding, accelerated the water flow from the interior to surface of the samples (Wen et al, 2020). So in the HA-MW method compared to other methods, the moisture was removed from the green pea layers more quickly.…”

Increases of Lipophilic Antioxidants and Anticancer Activity of Coix Seed Fermented by Monascus purpureus

“…For ABTS cation radical-scavenging activity, the measurement method was based on our previous research [ 4 ]. Briefly, 9 mL of ABTS solutions was mixed with 3 mL sample solutions with different concentrations (0–100 mg/mL).…”

“…DPPH free-radical-scavenging rate (%) = (1 − Abs sample /Abs blank ) × 100 (1) where Abs sample and Abs blank were the absorbance of the mixture of blank and sample with DPPH reagent after reaction, respectively. For ABTS cation radical-scavenging activity, the measurement method was based on our previous research [4]. Briefly, 9 mL of ABTS solutions was mixed with 3 mL sample solutions with different concentrations (0-100 mg/mL).…”

“…Numerous studies have reported different health benefits of the consumption of coix seed including decreasing in low-density lipoprotein cholesterol and increasing high-density lipoprotein cholesterol triglycerides, preventing fatty liver, reducing cell inflammation induced by lipoprotein oxidation, inhibiting allergic effects, etc. [ 3 , 4 , 5 ]. It has also been used for rheumatism, neuralgia, and diuretic medications and anticancer treatment [ 1 , 6 ].…”