No abstract

Spent coffee ground (SCG) is the main by-product of the instant coffee industry. In this study, wheat flour and dried SCG powder were used in the production of cookies with high fiber and antioxidant content. The objective of the study was to evaluate the effects of SCG ratio in the cookie formulation on nutritional quality, physical properties and sensory overall acceptability of the product. SCG is a rich source of dietary fiber. In 100 g dry weight of SCG, the total fiber and phenolic contents were 76.6 ± 0.58% and 3828±12 mg GAE/100g dry basis, respectively. When the SCG ratio increased from 0 to 0.25 of the composite flour weight, the dough had increased hardness and reduced adhesiveness, cohesiveness and springiness. An increase in the SCG ratio in the cookie formulation also decreased the diameter and thickness of the product but enhanced its hardness. Cookie samples supplemented with SCG had higher dietary fiber and phenolic content as well as a higher antioxidant activity than the control sample. Cookie samples were considered as high fiber food when the SCG ratio was 0.1 or higher. The use of SCG reduced the overall acceptability of cookies. When the ratio of SGC powder varied from 0.1 to 0.2, a sensory score of the obtained cookies was acceptable.

Coffee husks (CHs) is a high biological activity by-product of the coffee bean industry, but currently, in Vietnam, it has not been used properly in the food industry. This study was conducted to investigate the combined cellulolytic and pectinolytic enzymes to increase the polyphenol extractability of coffee husks. The red ripe Robusta coffee cherries from Dăklak province, Vietnam were blanched, peeled and the coffee husks was then extracted. The effects of pectinase content (from 0 to 800 U/gCHs), cellulase content (from 0 to 800 U/gCHs), pH (from 3.0 to 5.0), temperature (from 40◦C to 60◦C), CHs: solvent ratio (from 1: 6 to 1:12) and extracted time (from 60 minutes to 120 minutes) on soluble solid content (SSC), total polyphenol content (TPC) and antioxidant activity were investigated. The appropriate conditions for the treatment were pectinase dosage of 600 U/gCHs, cellulase dosage of 400 U/gCHs, pH 4.0, temperature 50◦C, CHs:soluble ratio = 1:10 and incubation time of 60 min under which the SSC, TPC and antioxidant activity of extract were highest by 60.60.4 g/100g dry weight of CHs, 200.5 gGAE /100g dry weight of CHs, 1.5 +/- 0.1 mMTE/g dry weight of extract (according to DPPH assay) and 1.5 +/- 0.1 mMTE/g dry weight of extract (according to DPPH assay). From this result, it can be seen that the extracted solution from coffee husk is a potential source for the production of soft drinks with high antioxidant activity.