Dairy Foods: Dairy Products

摘要

The present study evaluated the feasibility of the fortification of Greekstyleyogurt with a newly developed ingredient consisting of cheesewhey-spend coffee ground (CW-SCG) powder. The yogurts were analyzedusing a battery of tests, including whey production, water holdingcapacity, firmness, rheological properties, protein content, availablelysine, and antioxidant activity. The milk base was fortified to 15% drymatter with different skim milk powder to CW-SCG ratios (100/0, 75/25,25/75, and 0/100 wt./wt.). The addition of CW-SCG up to 75% did notsignificantly change the acidification curve when comparing with the controlsample (P > 0.05), reaching the target pH 4.7 after 270–300 min. Theavailable lysine decreased with the addition of CW-SCG, yielding valuesof 78.55 ± 1.56, 28.89 ± 2.45, 23.61 ± 4.42, 20.03 ± 2.71 mg per 100 g for0-, 25-, 75-, and 100-CW-SCG, respectively. The highest value of wheyproduction was obtained in those samples fortified with 100-CW-SCG(6.33 ± 0.35%), followed by 75- and 25-CW-SCG (5.17 ± 0.99 and 3.01± 0.81%, respectively). The antioxidant capacity increased proportionallyto the added CW-SCG powder, yielding values of 68.41 ± 2.78, 80.71 ±2.54, 100.51 ± 3.44, and 120.21 ± 3.18 μmol TEs per 100 g for 0-, 25-,75-, and 100-CW-SCG, respectively. Fortification of the yogurt with CWSCGdecreased the water holding capacity by 13 to 25%, depending onthe level of fortification. Similarly, the addition of CW-SCG significantlydecreased the hardness of the yogurts from 76.57 ± 1.18 to 30.27 ± 1.73 Ns (P < 0.05). Additionally, fortified yogurts with CW-SCG yielded a productwith less shear-thinning behavior as compared with control. The scanningelectron images of the fortified yogurts revealed the incorporation ofspent coffee ground particles within the protein network. Polyphenol-Proteinassociations may explain the texture and rheological behavior of theyogurts. The fortification of the yogurt up to 25% of CW-SCG yieldedcomparable properties than the control. The industrial developmentof fortification of yogurt with small amounts of CW-SCG will requirefurther studies to evaluate consumer acceptance and storage stability.