Walnut meal protein as a promising fat mimetic in low‐fat ice cream: mechanisms and quality control during storage

BACKGROUND Reducing dietary fat intake has become a prevalent health pursuit. In this study walnut meal protein (WP) with a protein content of 90.43% was utilized as a fat mimetic to optimize formulation, investigate component interaction mechanisms, and assess the storage quality of low‐fat ice cream. RESULTS Sensory evaluation and melting rate were used as indicators. The optimal processing conditions were determined to be a cream‐to‐WP ratio of 21:7, skimmed milk powder addition of 4.30%, and guar gum (GG) addition of 0.06%. Compared to the control sample, the WP and GG samples showed that the WP‐GG mix exhibited a smaller particle size, higher absolute zeta potential and viscosity, and lower surface tension. This suggests that the WP and GG mix can synergistically form a stable protein–polysaccharide composite gel network. Laser scanning confocal microscopy images confirmed that the WP‐GG sample mix exhibited a markedly dense and homogeneous structure. After 6 weeks of frozen storage, the WP‐GG sample demonstrated the highest overrun, the lowest melting rate, and the lowest hardness. At week 6, the syneresis rate was 70.42 ± 0.65% ( P < 0.05), indicating the best freeze–thaw stability. Furthermore, short‐term storage test results showed that on day 9 the peroxide value and acid value of the WP‐GG sample were only 1.48 ± 0.09 mmol kg −1 and 1.92 ± 0.07 mg g −1 , respectively. This confirmed that the steric hindrance between WP and GG maximally delayed lipid oxidation, effectively maintaining the oxidative and flavor stability of the ice cream. CONCLUSION This research provides a theoretical basis for the high‐value utilization of WP and the development of low‐fat ice cream.