Quality characteristics and antioxidant activity of bitter melon (Momordica charantia L.) dried by different methods

Abstract

Bitter melon has many nutrients and is excellent for many physiological functions. Here, bitter melon was dried by various methods (sun drying, hot air drying, freeze drying, and infrared drying), and the quality characteristics and antioxidant activity of the dried bitter melon were determined to improve the utilization of bitter melon as a food. The freeze-dried bitter melon had the highest soluble solid content (1.27 °Brix), and reducing sugar content of dried bitter melon was 220.33-247.13 mg/100 g. The pH and acidity of the dried bitter melons were 4.38-4.79 and 0.60-0.69%, respectively. The total amino acid content of the freeze-dried bitter melon was the highest, and the content of arginine, which has a bitter taste, was the highest in all the samples. Hot air-dried bitter melon had the highest polyphenol content, while the flavonoid content was the highest in infrared-dried bitter melon. However, there was no significant difference between the different drying methods. Antioxidant activity was significantly higher in hot air drying and infrared drying than in the other drying methods. Thus, freeze-dried bitter melon had superior physicochemical characteristics while infrared-dried and hot air-dried bitter melon had high antioxidant activity. Therefore, a proper drying method can be selected according to the requirement either as food materials or for processing of bitter melon.

Storage characteristics of two‐spotted cricket (Gryllus bimaculatus De Geer) powder according to drying method and storage temperature

“…After one day of freeze‐drying or hot air‐drying, the cricket samples had moisture contents of 2.4% and 1.9%, respectively (approximately 97% water removal by both methods); thus, there was no significant difference between the two drying methods based on the weight loss of samples, consistent with previous studies (Lee & Kim 2015; Youn et al . 2019). For comparison, we also dried the cricket samples at room temperature: it took 7 days for the moisture content of the crickets to reach 4.7% (data not shown).…”

LED White Light Treatment Delays Postharvest Senescence of ‘Zaosu’ Pear Fruit with Inhibited Chlorophyll Degradation

“…Currently, numerous approaches have been explored to preserve the green color of the fruit peel during storage and transportation. These include a controlled atmosphere, 1-methylcyclopropene (1-MCP), heat treatment, ozone, ethanol, plant growth regulators, plant extracts, and film preservatives [7][8][9][10][11][12][13][14][15][16]. Interestingly, researchers in the horticultural post-harvest field have shown great interest in light-emitting diodes (LEDs) due to their remarkable attributes.…”