FOOD AND BIOPROCESS TECHNOLOGY, vol.7, no.1, pp.204-211, 2014 (SCI-Expanded)
The objective of this study was to investigate storage and baking stability and in vitro digestibility of encapsulated phenolic powders obtained from micro- and nano-suspensions. In addition, it was aimed to study the influence of the incorporation of phenolic capsules into cakes on their quality and sensory attributes. Extraction of phenolic compounds from sour cherry pomace and concentration steps were used to obtain phenolic powders. Half of the concentrate was then freeze dried to produce extracted phenolic powder (EPP) and the rest was centrifuged at 10,000 rpm for 2 min before freeze drying to obtain purified extracted phenolic powder (PEPP). Phenolic powders were mixed with coating material containing 8 % maltodextrin and 2 % gum arabic at a core-to-coating ratio of 1:20 and homogenized by using ultrasound (160 W, 50 % pulse, 20 min). Micro-suspensions and nano-suspensions were prepared using EPP and PEPP, respectively. Suspensions were freeze dried to obtain capsules. Encapsulation had a positive effect on the hygroscopicity, in vitro digestibility and storage and baking stability of phenolic compounds. Loss of total phenolic content (TPC) of encapsulated EPP and PEPP was 10 % and 15 %, respectively, during storage at 43 % relative humidity (RH). Under the same conditions, uncoated EPP and PEPP lost TPC by 37 % and 43 %, respectively. There was no significant difference (p > 0.05) between encapsulated EPP and PEPP in terms of baking stability. Encapsulation was also effective in the masking of the flavor of the phenolic powders when capsules were incorporated into cakes. In addition, incorporation of capsules did not change quality parameters of cakes adversely.