Changes in the quality characteristics and chemical compounds of garlic shoots for blanching

Abstract

This study was performed to investigate changes in the quality characteristics and chemical compounds in garlic shoots by blanching for different time (0, 0.5, 1, 2, 3, and 4 min). The color (L, a, and b values), texture profile (hardness, springiness, chewiness, gumminess, and cohesiveness), total vitamin C, total sugar, total polyphenol and flavonoid, chlorophyll a and b contents, total pyruvate and thiosulfinate contents of the blanched garlic shoots were examined. As the blanching time increased, the L and b values decreased, while the a value increased. Hardness, chewiness, springiness and gumminess of the blanched shoots were significantly lowered with the increasing blanching time. Vitamin C content of raw garlic shoot was 1.62 mg/100 g while that of the blanched garlic shoots was 0.16~0.24 mg/100 g, implying vitamin C loss into blanching water and destruction by heat. The total sugar and polyphenol contents were fluctuated during blanching, but over 75% of their initial levels were retained under all blanching conditions. The total flavonoid contents increased as the blanching time increased. The chlorophyll a content did not show significant change with blanching time, but the chlorophyll b content significantly decreased. These results suggest that blanching for 2 min could be the best for retaining beneficial compounds and desirable quality of garlic shoot.

Effect of pretreatment conditions on quality characteristics and antioxidant activity in pak choi (Brassica rapa L. ssp. chinensis)

“…In the absence of such pretreatments, browning, decomposition due to microbial growth, and acidification can significantly degrade food quality (Kim et al, 2014). Blanching, a widely used pretreatment process for vegetables, plays a crucial role in maintaining vegetable texture stability, reducing food quality variation by deactivating specific enzymes, preventing browning, and offering a sterilization effect, thus establishing itself as a key food pretreatment technique (Jin and Choi 2001;Sim et al, 2016). While heating during pretreatment may lead to the destruction of unstable nutrients, it can also enhance the bioavailability of certain bioactive substances through facilitated hydrolysis, thereby offering nutritional benefits (Hwang and Nhuan, 2015).…”