Search

Pickering foams have great potential for applications in aerated foods, but their foaming ability and physical stability are still far from satisfactory. Herein, solid lipid particles (SLNs) were fabricated by using diacylglycerol of varying acyl chain lengths with modification by a protein. The SLNs showed different crystal polymorphisms and air–water interfacial activity. C14-DAG SLN with a contact angle ∼ 79° formed aqueous foam with supreme stability and high plasticity. Whey protein isolate and sodium caseinate (0.1 wt %) considerably enhanced the foamability and interfacial activity of SLNs and promoted the packing of particles at the bubble surface. However, high protein concentration caused foam destruction due to the competitive adsorption effect. β-sheet increased in protein after adsorption and changed the polymorphism and thermodynamic properties of SLN. The foam collapsing behaviors varied in the presence of protein. The results gave insights into fabricating ultrastable aqueous foams by using high-melting DAG particles. The obtained foams demonstrated good temperature sensitivity and plasticity, which showed promising application prospects in the food and cosmetic fields.

Fluid shortening is an important ingredient in the production of sponge cake. Peanut oil with 0, 43% and 85% of diacylglycerol content was used as the base oil. Different emulsifiers, such as glycerol monostearate, soy lecithin and sucrose ester, and their respective amounts, were investigated. It was found that the addition of emulsifiers had a positive effect on water-absorbing capacity, air-absorbing capacity and viscosity of the oils. Glycerol monostearate was the preferred emulsifier for fluid shortening with a recommended addition of 1.5%. The effects of different diacylglycerol content on fluid shortening and their impact on sponge cake production was also investigated. The onset oxidation temperature of the oil could be increased from 253.21 °C for PO-TAG-based fluid shortening to 263.70 °C for PO-DAG85-based fluid shortening. And the increase in diacylglycerol content leading to a lower specific gravity of the batter, which was 1.06 g/mL, 1.02 g/mL and 0.98 g/mL prepared by PO-DAG, PO-DAG43 and PO-DAG85 shortening, respectively. The results showed that diacylglycerols can be used as base oils in fluid shortening to improve the crystal network and stability of fluid shortenings, thereby reducing the specific gravity of the batter and improving the structural properties of the cake. This will extend the potential applications of diacylglycerols and increase the variety of base oils available for fluid shortening preparation.

In this study, a simple pH-colorimetric film was developed to detect the spoilage of pasteurized milk. The biosensor was fabricated by incorporating the pH-sensitive anthocyanins (AC) extracted from blue pea (Clitoria ternatea L.) flower into a starch-based edible film. The color responses of both AC aqueous extracts and edible films incorporated with different AC concentrations towards different pH buffers (pH 2–11) were measured using Ultraviolet–visible (UV–Vis) spectrophotometer and colorimeter, respectively. Based on the results, there were significant differences (p < 0.05) for both total color changes (∆E) and L*a*b color system of the pH-sensitive edible film in different pH buffers. It indicated that the AC incorporated edible films were able to exhibit color changes over a wide range of pH. The potential application of the pH-sensitive film in spoilage detection was then carried out. Color changes of the film in commercial pasteurized milk were measured at predetermined intervals (24, 48, and 72 h) under storage conditions of 25 °C. Meanwhile, milk samples were collected for the microbiological test [total plate count (TPC)]. Results showed that the pH-sensitive films were able to detect pH changes of pasteurized milk which was associated with milk spoilage with visually observable color changes from deep blue to a light blue and showed a significant ∆E (p < 0.05) of 19.95 ± 0.009. The ∆E of the films in spoilage detection has a significant correlation with the pH changes of milk (R = − 0.9932) and TPC with a desirable coefficient (R = 0.9918). Therefore, the pH-sensitive edible film can provide a highly sensitive and non-destructive way of monitoring the food quality or spoilage without creating safety issues in the food industry.

The effect of alkaline extraction/isoelectric precipitation and salt extraction/micellization on proximate composition, anti-nutritional content, amino acid composition and physicochemical properties of Moringa oleiferaprotein isolates were studied. Protein extractability was influenced by NaCl concentration, pH and temperature. The protein concentration of isoelectric and micellized isolates were 80% and 90%, respectively. Micellized isolates recorded higher yields (49%) than isoelectric isolates (15%). Both isolates were free of phytate, tannin, saponin and oxalate. Micellized isolates contained all essential amino acids except lysine and methionine which met the FAO/WHO recommendations for children; isoelectric isolates were deficient in methionine. Molecular weights of protein fractions were approximately 8.5–32.5 kDa. Micellization resulted in isolates with a lighter color, higher surface hydrophobicity (184) and higher transition enthalpy (109 J/g); isoelectric precipitation resulted in isolates with a higher denaturation temperature (190 °C). The results indicated that M. oleiferaprotein isolates could be a potential source of plant-based protein. The differences in physicochemical properties between the isolates indicate different functionalities and potentially different applications.