Cellulase Treatment of Acerola Seeds and Its Effect on Physicochemical Properties and Antioxidant Potential of Dietary Fiber-Rich Cookies

Acerola seeds are a by-product of the food industry, which is rich in dietary fiber and antioxidants. This study evaluated the effects of cellulase treatment conditions, including the initial moisture content, enzyme dose, and incubation time, on the insoluble, soluble, and total dietary fiber content of acerola seed powder (ASP). The blends of wheat flour with untreated and cellulase-treated ASP (0, 10, 15, 20, 25, and 30%, w/w) were then used to produce cookies. The suitable conditions for the enzymatic treatment were the initial moisture content of 6 g/g dry weight (DW), an enzyme dose of 10 U/g DW and incubation time of 90 min. The cookies produced from flour blends with ASP had higher dietary fiber, ascorbic acid and total phenolic contents, and antioxidant capacity, compared to the control cookies without ASP. Phytate content in the cookies obtained with the lowest level of fortification (10%, w/w) was similar to that in the control cookies. The use of cellulase-treated ASP resulted in a lower ratio of insoluble to soluble dietary fiber in the cookies compared to when the untreated ASP was used. In addition, the cookies with cellulase-treated ASP had lower hardness and higher fracturability values than those fortified with the untreated ASP. The overall acceptability of the cookies produced with ASP was higher or comparable to the control cookies. For the first time, the low-cost ASP was used to improve the nutritional quality of cookies. The treated ASP is a novel promising dietary fiber- and antioxidant-rich ingredient for cookie preparation.