Stabilisation of sodium caseinate hydrolysate foams

Impact of Enzymatic Hydrolysis and Heat Inactivation on the Physicochemical Properties of Milk Protein Hydrolysates

This study determined the physicochemical properties (apparent viscosity (ηapp), turbidity (A550nm), particle size and molecular mass distribution) of hydrolysates generated from whey protein concentrate (WPC), milk protein concentrate (MPC) and sodium caseinate (NaCN), following incubation with Debitrase HYW20™ and Prolyve™ at 50 °C, pH 7.0 for 1 and 4 h, before and after heat inactivation (80 °C for 10 min). The degree of hydrolysis (DH) increased with incubation time, giving values of 6.56%, 8.17% and 9.48%, following 1 h hydrolysis of WPC, MPC and NaCN with Debitrase HYW20™, and 12.04%, 15.74% and 17.78%, respectively, following 4 h incubation. These DHs were significantly higher compared to those obtained following 4 h incubation with Prolyve™. Hydrolysis with Debitrase HYW20™ gave >40% of peptides with molecular masses < 1 kDa for all substrates, which was higher than the value obtained following hydrolysis with Prolyve™. The effect of hydrolysis on the physicochemical properties was substrate dependent, since ηapp decreased in WPC and NaCN hydrolysates, particle size decreased for all the substrates, with aggregate formation for MPC, and turbidity decreased in WPC and MPC hydrolysates, while it increased in NaCN hydrolysates. The physical properties of the hydrolysates were influenced by the enzyme thermal inactivation step in a DH-dependent manner, with no significant effect on turbidity and viscosity for hydrolysates at higher DHs.

Effect of heat treatments on foaming and physico-chemical properties of bovine and camel sodium caseinate

The objective of this study was to examine the foaming properties of sodium caseinates (Na-cas) extracted from bovine and camel fresh milks after heating at 70, 80, 90 and 100°C for 30 min at laboratory scale. Experimental results indicated that greater foam was obtained with camel Na-cas than with bovine Na-cas at all heating temperatures due to the higher β-casein content in camel caseins (~53.4% of total proteins, RP-HPLC results). Increasing heat-treatment temperature to 100°C significantly enhanced the foaming properties by raising surface hydrophobicity and decreasing electronegative charge as well as interfacial tension values upon heating. This study concluded that camel Na-cas has important foaming properties in agricultural and food industries.

Trends in foam mat drying of foods: Special emphasis on hybrid foam mat drying technology

Dehydration of foods is not simply a preservation technique in the present era, rather an important food processing operation which has many benefits in addition to enhancement of shelf life of foods. There are various methods of drying foods and most of them are unique in their own way. Liquid foods can be dried in many ways and foam mat drying is one such method which is being researched frequently for its potential use at commercial level. Foam mat drying has got almost all the features to be a commercially successful method of drying. It is a simple technique and has shown good results in drying of liquid foods with low glass transition temperature. Hybridization of this method has shown the results that make this technology look even more promising than the conventional one. Studies on freeze drying, vacuum drying and microwave drying of foam have indicated encouraging results with respect to drying kinetics and product quality. This review presents an overview of foam mat drying of foods. The procedure and technology of this method of drying have been summarized with an intention to make them easy to understand. The emphasis is, however, on the hybrid foam mat drying technology.

Foaming properties and air-water interfacial behavior of corn protein hydrolyzate-tannic acid complexes

The complexation of corn protein hydrolyzate (CPH) with tannic acid (TA) was utilized to improve the foaming properties of CPH itself, and the air-water interfacial behavior of CPH-TA complex was also investigated. The results showed that the surface hydrophobicity of pure CPH was significantly decreased in bulk solution after the complexation with TA. Compared with pure CPH, the foams stabilized by CPH-TA complex showed higher interfacial thickness between the bubbles, which well explained the better long term stability of the corresponding foams. Therefore, the complexation maintained the good foaming capacity of CPH itself, but considerably increased its foam stability. Moreover, the air-water interfacial behavior study demonstrated that the complexation slightly decreased the interfacial activity of CPH itself, but considerably increased its interfacial viscoelasticity, suggesting more stable of the air-water interface stabilized by CPH-TA complex compared with that stabilized by CPH alone. These findings indicated that foaming properties of the surface active components were closely related with its air-water interfacial behavior. The study suggested that CPH-TA complex could be used as a stabilizer in constructing the peptides-based foams.