Perilla seed protein (PSP) was extracted from defatted perilla seed meal and applied in oil-in-water (O/W) emulsions as an emulsifier. We investigated the influences of protein concentration (0.25–1.5 wt %), pH (3.0–9.0), NaCl concentration (0–350 mmol/L) and thermal treatment (70–90 °C, 30 min) on the physical characteristics of O/W emulsions, including volume-average diameter, ζ-potential, interfacial protein concentration, microstructure and so on. Results showed that increasing PSP concentration would decrease the d_4,3 and a 1.0 wt % PSP concentration was sufficient to ensure the stability of emulsion. Under pH 3.0–9.0, emulsions were stable except at pH 3.0–5.0 which was proximal to the isoelectric point (pH 4.5) of PSP. At high NaCl concentrations (250–350 mmol/L), the emulsions exhibited relatively lower absolute ζ-potential values and a large number of aggregated droplets. A moderate thermal treatment temperature (e.g., 70 °C) was favorable for the emulsion against aggregation and creaming. However, when 90 °C thermal treatment was performed, a clear layer separation was observed after 2 weeks storage and the emulsion showed a poor stability. The findings of this work are of great importance for the utilization and development of PSP as an emulsifier for food emulsions.

The objective of this work was to examine the application of high purity diacylglycerol (DAG) oil in whipped cream as a partial substitute of hydrogenated palm kernel oil (HPKO). The DAG-enriched oil, with a purity of 94.50 wt%, was prepared via the enzymatic glycerolysis of palm oil/peanut oil blend and followed by molecular distillation. The substitute levels of 0, 10%, 20%, 30% and 40% (w/w) DAG for HPKO were employed, and the effects of DAG on emulsion properties, whipping characteristics and sensory quality were investigated. The result showed DAG oil promoted partial coalescence of fat globules in emulsion. As 0–20% DAG was involved in the emulsion, the average particle size (d_3,2), surface protein concentration (SPC), partial coalescence of fat and overrun increased during whipping. The results of textural characteristics and sensory evaluation showed that 10-30% DAG substitute for HPKO would be successfully applied in whipped cream.