Functionality of strawberry powder on frozen dairy desserts.

This study investigated the potential use of freeze-dried strawberry powder as a stabilizer in frozen dairy desserts. Five different dessert mixes were developed that contained 0%, 2.5%, 3%, 3.5%, and 4% strawberry powder. An additional dessert using strawberry extract was prepared to differentiate the effects of dietary fiber from the effect of polyphenols on sample properties. The rheological and physical characteristics of dessert mixes, fresh dessert, and stored dessert were studied. The addition of strawberry powder to dairy desserts caused an increase in the mix viscosity and a decrease in hardness and meltdown values. Complete avoidance of meltdown was achieved with the addition of 3% or greater amount of strawberry powder. The viscosity of mixes was enhanced due to the increase of total solids in the serum phase and the formation of hydrated and gel-like networks in the presence of cellulosic material, pectin, and calcium. The increase in viscosity and unfrozen water with the addition of strawberry powder also caused a reduction in ice crystallization, which resulted in softer and more stable desserts over time.

Phenolics and Antioxidant Capacity of Pitted Olive Pomace Affected by Three Drying Technologies.

This study investigated drum-drying's ability to produce dried food-grade olive pomace as a potential food ingredient that is more nutritionally dense than its freeze-dried and hot-air dried counterparts. The pits and skin were removed from fresh olive pomace, and the remaining pulp was dried to <5% moisture through freeze-drying, hot-air drying, and drum-drying at two rotational speeds. The drying treatments had no significant (P ≤ 0.05) effect on the olive pomace's fat or dietary fiber contents but did increase the L* , a* , and b* color parameter values. Although all the drying treatments significantly (P ≤ 0.05) decreased the fresh olive pomace's antioxidant capacity, drum-drying preserved the olive pomace's antioxidant capacity significantly (P ≤ 0.05) better than freeze-drying and hot-air drying. The drum-dried samples had concentrations of caffeic acid and verbascoside that were significantly (P ≤ 0.05) higher than the other dried pomace samples and were not significantly (P ≤ 0.05) different from the fresh pomace. The drum-dried olive pomace contained concentrations of hydroxytyrosol, tyrosol, vanillic acid, luteolin-7-glucoside, and rutin that were not significantly (P ≤ 0.05) different from the dried sample with the highest concentration of each respective phenolic compound. No oleuropein was found in the fresh or dried olive pomace. The results of this study show that drum-drying is an energy efficient method for converting olive pomace into a stable food-grade supplement that preserves its high phenolic, antioxidant, and dietary fiber contents to potentially benefit human health when incorporated into food or supplement products. PRACTICAL APPLICATION: Pitting and drying converts the olive pomace into a stable form that is free of physical hazards and could be incorporated into food products to increase their nutritional quality through olive pomaces' high fiber, antioxidant, and phenolic contents. Drum-drying allows food-grade olive pomace to retain higher amounts of beneficial soluble phenolics and a higher antioxidant capacity than conventional drying methods, thus furthering olive pomace's potential valorization as a food ingredient.