Comparative Testing of Powder Caking

Miyeokgui (Undaria pinnatifida Sporophyll) Characteristic under Different Relative Humidity: Microbial Safety, Antioxidant Activity, Ascorbic Acid, Fucoxanthin, α-/β-/γ-Tocopherol Contents

This study aimed to investigate the effects of different relative humidities (%) on the microbial safety, antioxidant activity, ascorbic acid, fucoxanthin, and tocopherol contents of Undaria pinnatifida sporophyll powder (UPSP) stored for 4 weeks. The caking phenomenon did not occur in the 11-53% relative humidity conditions, but it did in the 69%, 81%, and 93% relative humidity conditions with caking index values of 88.30%, 99.75%, and 99.98%, respectively. The aerobic bacterial contents increased drastically in samples stored at 69-93% relative humidity. Ascorbic acid was unstable at high relative humidity, but fucoxanthin and tocopherol were more unstable at low relative humidity. Therefore, it was most stable at intermediate relative humidity. The 69% relative humidity sample had higher DPPH (12.57 g BHAE/kg), ABTS (4.87 g AAE/kg), and FRAP (4.60 g Fe (II)/kg) than the other samples. This study could be helpful for the storage and transport of UPSP under optimum relative humidity conditions, which can significantly prevent quality losses.

Rapidly evaluating the caking tendency of sugar alcohols by developing a crystal bridge growth model: A case study of xylitol

Caking of crystalline sugar alcohols is a deleterious and undesired agglomeration process during storage in the food industry. Compared with the time-consuming and labor-intensive conventional caking assessment methods, this work develops a rapid methodology for evaluation of the critical caking cycle of xylitol with over 85% time-saving and 90% labor-saving while guaranteeing the precision accuracy. By developing a Caking-Hygroscopicity-Particle size crystal bridge growth model, the correlation and quantitative relationships among hygroscopic properties, particle size and the critical caking cycle are firstly established and confirmed, which can greatly simplify the most time-consuming and laborious experiments of water sorption measurements and caking tests. Besides, the knowledge obtained can help guide the rapid selection of storage humidity conditions and appropriate particle size distributions for maintaining the desired properties and competitive marketability of crystalline sugar alcohols.