Changes in the Radical‐Scavenging Activity of Bitter Gourd (Momordica charantia L.) during Freezing and Frozen Storage with or without Blanching

Abstract

The effects of blanching, freezing, and frozen storage on the retention of radical-scavenging activity (RSA), total phenolics, and ascorbic acid in bitter gourd were investigated. Blanching of sliced bitter gourd resulted in considerable losses of RSA and total phenolics, and most extensively, of ascorbic acid. In the subsequent frozen storage at -18 degrees C, RSA and total phenolic content of unblanched and blanched bitter gourd underwent little change for 90 d then gradually declined, but at -40 degrees C, they practically remained unchanged throughout the entire storage period. On the contrary, ascorbic acid content of both unblanched and blanched bitter gourd decreased abruptly at the early stage in frozen storage. The results show that blanching of bitter gourd improves the retention of RSA and total phenolics during subsequent frozen storage but markedly aggravated loss of ascorbic acid. Finally, it is to be noted that RSA, total phenolics, and ascorbic acid originally contained in the raw bitter gourd were overall best retained by quick freezing followed by frozen storage at -40 degrees C without preceding blanching.

Comparative sudies on dehydration of mint (Mentha arvensis) by open sun drying, solar drying and hot air cabinet drying

“…6 Polyphenol content: The results also showed significant decrease in the polyphenol content in case differently treated and differently dried mint. The decrease in phenolic compounds was in accordance with the studies of Myojin et al (2008) and Wen et al (2010). These researchers reported that the phenolic compounds in the vegetables studied were sensitive to heat and the heat treatment caused a significant loss of phenolic content which leached into the water (Fig.…”

Attenuation of experimentally induced diabetic neuropathy in association with reduced oxidative-nitrosative stress by chronic administration of <i>Momordica charantia</i>

“…Many agents affecting nociceptive response also affect motor and sensory responses; therefore, motor coordination was evaluated using rota rod test. It is reported that antioxidant activity, total phenolics and ascorbic acid content of MC are best retained by quick freezing [16], therefore, lyophilized powder obtained by continuous freeze drying of fresh juice was used in the study. Strict glycemic control and use of antioxidants has been reported to slow/ reverses the progression of diabetic neuropathy [9,10].…”

“…Various biologically active chemicals reported from MC include glycosides, saponins, alkaloids, fixed oils, triterpenes, polyphenols, proteins and steroids. The beneficial effects of MC in diabetes are attributed to active constituents like charantin, insulin-like peptide (plant (p)-insulin), cucurbutanoids, momordicin, and oleanolic acids [14,15] while as antioxidant activity is mainly due to its total phenolic and ascorbic acid content [16].…”

Determination of metrafenone in bitter gourd and soil by GC with ECD

“…It contains substances with antidiabetic properties such as charantin, vicine, polypeptide-pand other unspecific bioactive components such as antioxidants (Michael & Gudrun, 2006). This vegetable has many medicinal applications which is beneficial against piles, blood and respiratory disorders (Myojin et al, 2008). Several kinds of diseases affect the growth of bitter gourd including powdery mildew and downy mildew among others.…”