Effect of Dehydration on Raspberries: Polyphenol and Anthocyanin Retention, Antioxidant Capacity, and Antiadipogenic Activity

• Published in: Journal of food science Vol. 75; no. 1; pp. H5 - H12
• Main Authors: Mejia-Meza, E.I, Yáñez, J.A, Remsberg, C.M, Takemoto, J.K, Davies, N.M, Rasco, B, Clary, C
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 2010; Wiley; Wiley Subscription Services, Inc
• Subjects: Air; anthocyanin; anthocyanins; Anthocyanins - analysis; antiadipogenic activity; antioxidant activity; antioxidant capacity; Antioxidants; Antioxidants - analysis; antioxidative activities; Berries; Biological and medical sciences; Comparative analysis; Dehydration; dried fruit; drying; drying quality; Effects; Ellagic Acid - analysis; Flavonoids - analysis; food analysis; Food engineering; Food Handling - methods; Food industries; food processing quality; Food science; Freeze Drying; fruit; Fruit - chemistry; Fruit and vegetable industries; fruit composition; functional foods; Fundamental and applied biological sciences. Psychology; General aspects; Glycosides - analysis; Hydrolysis; lipogenesis; Microwaves; nutrient content; nutritive value; Phenols - analysis; Polyphenols; Quercetin - analysis; raspberries; Solutions; Anthocyanin; Polyphenol; antioxidative activities; Fruit; antioxidant capacity; Raspberry; Pigments; Antioxidant; Dehydration; Retention; Flavonoid
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/j.1750-3841.2009.01383.x

Fresh and dried raspberries prepared by freeze drying (FD), microwave-vacuum (MIVAC), hot-air drying (HAD), and a combination of hot-air drying and microwave-vacuum (HAD/MIVAC) drying methods were evaluated for polyphenol retention, total polyphenol and anthocyanin contents, total antioxidant capacity, and antiadipogenic activity (the inhibition of fat cell development). Ellagic acid and quercetin were present in the largest concentrations in fresh and dehydrated raspberries. Dehydration led to a loss of polyphenols and anthocyanins and antioxidant capacity. Polyphenols (aglycone form) were retained in the greatest amount: 20% (freeze dried) to 30% (HAD/MIVAC) (fresh = 100%). A total of 30% of polyphenols (glycoside form) were retained in raspberries dried by the HAD/MIVAC methods with 5% of retention observed for raspberries dried by FD, HAD, or MIVAC. FD and MIVAC resulted in higher retention of anthocyanins (aglycone form) than other drying methods. It was also observed that antioxidant activity was reduced by dehydration. Adipogenesis was inhibited by polyphenolic glycosides (30%) and aglycones (30% to 40%) in fresh and HAD/MIVAC raspberries. Extracts from dried raspberries by HAD/MIVAC methods were relatively more effective at inhibiting adipogenesis compared to HAD and FD dried raspberries.