Effect of particle size, concentration, temperature and pH on rheological properties of shallots flour

Partial replacement of saturated fats in liver pâté by an olive oil-in-water emulsion containing β-glucan shows no compromise in sensory and storage oxidation of lipids and protein

BACKGROUND

The consumption of olive oil has been shown to have a positive effect on preventing obesity and hypertension. At the same time, it is recommended to avoid processed meat products as they contain saturated fats. The inclusion of highly unsaturated lipids in food products can lead to rapid oxidation and deterioration of sensory characteristics. The objective of the current work was to encapsulate olive oil and incorporate it into traditional Polish liver pâté. The oil-in-water emulsions were formulated with varying levels of oat β-glucan and were evaluated for droplet size, pH, encapsulation efficiency and rheology. The liver pâtés made using the emulsions with and without β-glucan were then evaluated for pH, texture, colour, lipid and protein oxidation, thermal stability and sensory properties.

RESULTS

The results showed that the oil-in-water emulsions had a 100% encapsulation rate of olive oil after 30 days of storage at 4 °C, regardless of the presence of β-glucan. Although the texture of the emulsion-enriched liver pâté was different from that of the control, this difference was reduced when β-glucan was added to the emulsion and then to the pâté matrix.

CONCLUSION

Replacing 50% of animal fat with an olive oil emulsion enriched with β-glucan did not result in any compromise of sensory properties, increase lipid or protein oxidation. These results suggest that it is possible to replace saturated lipids with omega-3-rich olive oil. © 2024 Society of Chemical Industry.

Effect of atmospheric cold plasma treatment on acid gelation properties of skim milk: Rheology and textural studies

Cold plasma processing is a non-thermal food processing technique that has been shown to improve the gelling properties of plant proteins by altering their structure through oxidation and crosslinking. This study aimed to investigate the effects of cold plasma treatment on the rheological properties of skim milk under different conditions, focusing on the impact of feed gas and treatment time on skim milk's sulfhydryl content, flow properties, and acid gelling behavior. Results showed that free sulfhydryl content decreased with treatment time, with a notable reduction observed after 2 min of N2-O2 plasma treatment. Skim milk treated with N2 plasma experienced a more gradual decrease in free SH content. Cold plasma increased skim milk viscosity over time. N2-O2 plasma treatment significantly affected G'40 and G'4 storage moduli, with an increase observed after 2 min of exposure but no change beyond that time. Acid gels' greenness (a* value) decreased with increasing treatment time compared to the control. Acid gel firmness of milk treated with N2-O2 plasma for 1 min significantly increased from 1.804 N to 1.912 N, and further to 2.072 N after 2 min of treatment. However, longer exposure times led to lower firmness in gels. N2 plasma treatment also significantly impacted acid gel firmness. Syneresis in acid gels decreased from 63.4 % to 57.7 % and 58.7 % after 1 and 2 min of N2-O2 plasma treatment, respectively, but increased to about 70 % after 4 min. Acid gels made from milk treated with N2 plasma experienced considerably less syneresis. The cold plasma treatment under different conditions significantly affected the properties of skim milk, with various impacts on sulfhydryl content, flow properties, and acid gelling behavior. These findings demonstrate the potential applications of cold plasma processing in the food industry to improve product properties.

Effects of Concentration and Type of Lipids on the Droplet Size, Encapsulation, Colour and Viscosity in the Oil-in-Water Emulsions Stabilised by Rapeseed Protein

The objective of this study was to extract the rapeseed protein from by-products and further examine the effect of lab-made rapeseed protein on the droplet size, microstructure, colour, encapsulation and apparent viscosity of emulsions. Rapeseed protein-stabilised emulsions with an increasing gradient of milk fat or rapeseed oil (10, 20, 30, 40 and 50%, v/v) were fabricated using a high shear rate homogenisation. All emulsions showed 100% oil encapsulation for 30 days of storage, irrespective of lipid type and the concentration used. Rapeseed oil emulsions were stable against coalescence, whereas the milk fat emulsion showed a partial micro-coalescence. The apparent viscosity of emulsions raised with increased lipid concentrations. Each of the emulsions showed a shear thinning behaviour, a typical behaviour of non-Newtonian fluids. The average droplet size was raised in milk fat and rapeseed oil emulsions when the concentration of lipids increased. A simple approach to manufacturing stable emulsions offers a feasible hint to convert protein-rich by-products into a valuable carrier of saturated or unsaturated lipids for the design of foods with a targeted lipid profile.

White Finger Millet (KMR-340): A comparative study to determine the effect of processing and their characterisation

The white finger millet (WFM) KMR-340 flour: native (untreated), roasted (120 °C, 5 min) and germinated (30 ± 3 °C, 48 hrs) were characterised (nutritional, functional, thermal, pasting and rheological properties, X-ray diffraction, and FTIR). Germination significantly increased the protein, fibre, calcium, magnesium and antioxidant activity (14.66%) whereas decreased total ash, carbohydrate and fat. However, roasting significantly increased the carbohydrate, ash, fat, fibre and protein content. Roasting and germination significantly increased the non-essential amino acid contents, whereas the essential amino acid contents were reduced upon pretreatments. Though, processing methods improved the functional properties of millet flours, the pasting properties of the roasted and germinated flours were significantly varied from native flour. Rheological measurements revealed that all flour samples showed shear thinning behaviour (n < 1). The XRD patterns revealed that the percentage crystallinity reduced in the processed flours.