Packaging With Different Color Bags Under Light Exposure Improves Baby Mustard (Brassica juncea var. gemmifera) Postharvest Preservation.

Effect of packaging baby mustard into bags of different color under light exposure on its visual quality and the content of chlorophyll, carotenoids, and glucosinolates at 20°C was investigated. Packaging with seven color bags under light exposure prolonged the shelf life, especially green (GB), blue (BB), and transparent (TB) bags with holes, and their shelf life was 1.7, 1.6, and 1.6 times that of the control, respectively. The GB and BB treatments delayed the deterioration of the sensory quality in baby mustard during storage. The BB and TB treatments not only increased chlorophyll and carotenoids content in baby mustard during storage but also enhanced the accumulation of glucosinolates by inhibiting their degradation, especially the BB treatment. Overall, the results demonstrate that the BB treatment is a promising technique for maintaining the postharvest quality of baby mustard.

Light irradiation maintains the sensory quality, health-promoting phytochemicals, and antioxidant capacity of post-harvest baby mustard.

The ability of white, red, and blue irradiation to maintain sensory quality, health-promoting compounds, and antioxidant capacity, and regulate glucosinolate metabolism-related gene expression in post-harvest baby mustard was studied. Irradiation with 80 µmol m-2 s-1 extended the shelf life of post-harvest baby mustard. Irradiation delayed the increase in weight loss and the decrease in sensory parameter scores and the levels of ascorbic acid, total phenolics, glucosinolate, and antioxidant capacity during storage of baby mustard. Irradiation induced the expression of glucosinolate biosynthesis genes and inhibited glucosinolate degradation gene expression. The glucosinolate content and glucosinolate metabolism-related gene expression in post-harvest baby mustard were higher under white and red light irradiation compared with blue light irradiation. These findings indicate that irradiation (80 µmol m-2 s-1 ), especially of white and red light, is an effective technique for maintaining the sensory and nutritional qualities in post-harvest baby mustard stored at 20°C. PRACTICAL APPLICATION: This study was to evaluate the effect of white, red, and blue irradiation on the sensory quality, health-promoting compounds, antioxidant capacity, and glucosinolate metabolism-related gene expression of baby mustard during post-harvest storage, providing an effective and sustainable post-harvest method to extend shelf life and maintain the post-harvest quality of baby mustard under ambient temperature storage. Irradiation (80 µmol m-2 s-1 ), especially of white and red light, is an effective technique for maintaining the sensory and nutritional qualities in post-harvest baby mustard stored at 20°C.

Modified Atmosphere Packaging Maintains the Sensory and Nutritional Qualities of Post-harvest Baby Mustard During Low-Temperature Storage.

Baby mustard is a popular, yet highly perishable, Brassica vegetable. There is a need to develop effective methods for maintaining post-harvest qualities of baby mustard. Here, the lateral buds of baby mustard were packed in transparent polyethylene bags with no holes (M0), 6 mm in diameter holes (M1), or 12 mm in diameter holes (M2) and stored at 4°C. The effect of different modified atmosphere packaging (MAP) treatments on the sensory quality, health-promoting compounds, and antioxidant capacity was investigated by comparison with non-wrapped baby mustard. M1 and M2 delayed sensory quality deterioration and slowed declines in the content of ascorbic acid, total phenolics, and glucosinolates and antioxidant capacity during storage. M1 was most effective in prolonging the shelf life (three additional days compared with control lateral buds) and maintaining the content of glucosinolates. However, M0 accelerated the decline in the odor score, acceptability score, and ascorbic acid content and shortened the shelf life of baby mustard by more than 5 d compared with the control. These findings indicate that the effect of MAP treatment depends on the size of the holes in the bag. Based on these results, M1 was an alternative method for prolonging the shelf life and maintaining post-harvest qualities of baby mustard stored at 4°C.

Characterization of BoaCRTISO Reveals Its Role in Carotenoid Biosynthesis in Chinese Kale.

Carotenoids are organic pigments that play an important role in both plant coloration and human health; they are a critical subject in molecular breeding due to growing demand for natural molecules in both food and medicine. In this study, we focus upon characterizing BoaCRTISO, the carotenoid isomerase gene before the branch of the carotenoid biosynthetic pathway, which is expressed in all organs and developmental stages of Chinese kale, and BoaCRTISO, which is located in the chloroplast. The expression of BoaCRTISO is induced by strong light, red and blue combined light, and gibberellic acid treatment, but it is suppressed by darkness and abscisic acid treatment. We obtained BoaCRTISO-silenced plants via virus-induced gene silencing technology, and the silence efficiencies ranged from 52 to 77%. The expressions of most carotenoid and chlorophyll biosynthetic genes in BoaCRTISO-silenced plants were downregulated, and the contents of carotenoids and chlorophyll were reduced. Meanwhile, BoaCRTISO-silenced plants exhibited phenotypes of yellowing leaves and inhibited growth. This functional characterization of BoaCRTISO provides insight for the biosynthesis and regulation of carotenoid in Chinese kale.

The effect of different thawing methods on the health-promoting compounds and antioxidant capacity in frozen baby mustard.

The effects of five domestic thawing methods, including air thawing (AIR), water thawing with bags (W + B), water thawing without bags (W - B), refrigerator thawing (REF), and microwave thawing (MIC), on the main health-promoting compounds and antioxidant capacity in both unblanched and blanched baby mustard were investigated in this study. The results showed that different thawing methods markedly affected the health-promoting compounds and antioxidant capacity of baby mustard. MIC better retained the overall nutritional quality of frozen baby mustard compared with the four other treatments. AIR led to significant decreases in the glucosinolate contents in unblanched and blanched baby mustard. W + B led to significant decreases in the total phenols contents and antioxidant capacity levels in unblanched and blanched baby mustard, as well as the ascorbic acid content in unblanched baby mustard. W + B led to a significant decrease in the FRAP level in unblanched baby mustard, as well as the glucosinolate and ascorbic acid contents and ABTS level in blanched baby mustard. REF led to significant decreases in glucosinolates and proanthocyanidins contents in unblanched baby mustard, as well as the ascorbic acid content in blanched baby mustard. Furthermore, the thawing time was greatly shortened by MIC (only approximately 1 min). Thus, MIC was the optimal thawing method for frozen baby mustard regardless of whether it was blanched, as MIC best preserved nutritional quality and reduced the thawing time.

Low-temperature storage after harvest retards the deterioration in the sensory quality, health-promoting compounds, and antioxidant capacity of baby mustard.

Baby mustard is a perishable vegetable, and thus its distribution and sale as fresh produce face several challenges. However, little effort has been made to identify optimal techniques for postharvest storage of baby mustard. Here, we evaluated the sensory quality, health-promoting compounds, and antioxidant capacity of baby mustard during postharvest storage for 6 days at low temperature (4 °C, LT) and ambient temperature (20 °C). The results showed that visual quality scores, weight, firmness, the contents of most glucosinolates, and the ferric reducing antioxidant power value decreased in the lateral buds of baby mustard during both treatments; however, LT treatment delayed declines in these characteristics. In addition, the contents of glucose, fructose, total soluble sugars, ascorbic acid, and flavonoids, as well as the level of 2,2-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid), decreased considerably throughout the storage period, sucrose content increased throughout the storage period, and the contents of proanthocyanidin and total phenolics first increased and then decreased at 20 °C; however, their contents remained stable throughout the storage period under the LT treatment. These findings indicate that LT provides a promising approach for maintaining the sensory and nutritional quality of baby mustard.