Effect of ultrafiltration retentates and whey protein concentrates on ice cream quality during storage

Ultrafiltration retentates (concentrated to three times) and whey protein concentrates were used to replace different levels of SNF in vanilla ice cream at 25, 50, or 75% and 25, 50, 75, or 100%, respectively. All mixes were formulated to make an ice cream containing 12% fat, 9.7% SNF, 12% sucrose, 4% corn syrup solids, and .3% stabilizer-emulsifier. Ice cream mixes were evaluated for pH and viscosity after 24 h of aging. These mixes were processed through an HTST pilot plant system and a 4.73-L (5-qt) batch freezer at 80% overrun. The drawing temperature was measured at this time. The ice creams were evaluated for chemical composition, microbiological quality, and sensory properties at 1, 30, and 90 d of storage. Heat shock stability and melt-down properties were tested after 30 d of storage. The results showed that the pH was affected significantly (P < .05) by substitutions of whey protein concentrate and UF retentate. The pH and viscosity increased as the percentage of UF retentate substitution increased, but these two parameters decreased as the percentage of substitution with whey protein concentrate increased. Substitution with the concentrate at 75 and 100% significantly (P < .05) decreased the viscosity compared with the UF retentate products. The protein and lactose values were affected by replacing different levels of UF retentate in ice cream mixes. Protein values of 3.88 to 4.53% in UF retentate products were higher than those of ice, cream with whey protein concentrate at 3.18 to 3.55% (P < .05). Sensory evaluation results showed that ice cream made with substitution of SNF with UF retentate had higher flavor and body and texture scores than that made with whey protein concentrate. Substitution with 25% UF retentate produced the highest mean flavor score of 8.31.