The effect of biopolymer-water interaction on relaxation phenomena in blackcurrant pectin solutions

Development and physicochemical characteristics of multicomponent freeze-dried snacks obtained with blackcurrant pomace powder and calcium ions as structuring agents

Consumers seek healthy and sustainable products, whereas the food industry faces the challenge of processing by-products management. The application of fruit pomace as an additive could be a solution addressing the needs of both consumers and producers. The research objective has been to assess the effect of dried blackcurrant pomace powder (BP) and calcium ions in varied concentration on the physicochemical properties of multicomponent freeze-dried snacks as compared to the influence of low-methoxyl pectin (LMP). The snacks were prepared using varied content of BP (1, 3, 5%) and calcium lactate (0, 0.01, 0.05%). Water content and activity, hygroscopic properties, structure, texture, colour, polyphenols content (TPC), and antioxidant activity were analysed. The addition of BP resulted in lowering water activity and porosity. The microstructure of the snacks consisted of a large number of small and unevenly distributed pores. Consequently, the reduction of hygroscopic properties with the growing amount of BP was observed. Applied additives strengthened the structure and caused changes in compression curves indicating enhanced hardness and crispiness. The effect given by 5% of BP was comparable to that obtained with 0.5% of LMP. Additionally, blackcurrant pomace infusion increased TPC and enhanced antioxidant activity but it also caused significant changes in the colour of the snacks. Overall, obtained results have shown that dried blackcurrant pomace powder (BP) can be successfully applied as a food additive supporting stability, texture, and bioactive compounds content, thus fortifying the physicochemical properties of freeze-dried fruit and vegetable snacks.

The effect of apple pomace powder and calcium ions on selected physicochemical properties of freeze-dried carrot-orange-ginger snacks

BACKGROUND

This study aimed to determine the effect of various amounts of dried apple pomace (AP) powder and calcium ions on selected physicochemical properties of restructured freeze-dried snacks in comparison with products obtained with low-methoxyl pectin (LMP). The material was prepared using frozen carrot, orange concentrate, ginger, water, and various concentrations of AP (1, 3, 5%) and calcium lactate (0, 0.01, 0.05%). The reference samples were without additives, and with 0.5 or 1.5% of LMP combined with 0.01% of calcium lactate.

RESULTS

The material was studied in terms of water content and activity, hygroscopic properties, structure, texture, color, and polyphenol content (TPC), and antioxidant activity. The addition of AP resulted in reducing water activity and porosity. As a consequence of the increasing density of the structure, the reduction of hygroscopic properties by up to 16% followed the increasing amount of AP. Apple pomace and calcium ions strengthened the structure. The addition of 3% and 5% of AP gave a hardening effect close to or better than 0.5% LMP. Because of the pigment dilution, LMP caused significantly greater total color change than AP. The incorporation of AP also increased TPC and enhanced antioxidant activity in comparison with the reference materials by up to 18%.

CONCLUSION

The results showed that dried AP powder can be applied successfully as an additive enhancing stability, texture and bioactive compound content, thus fortifying the physicochemical properties of restructured freeze-dried fruit and vegetable snacks. © 2023 Society of Chemical Industry.

The Effect of Pectin Branching on the Textural and Swelling Properties of Gel Beads Obtained during Continuous External Gelation Process

The aim of the study was to produce gel beads under continuous conditions. Pectins obtained from black and red currants and commercial apple pectin were used as the material. For the production of gel beads, a self-designed device was used. The designed device allows for the production of gel beads in a continuous process, the properties of which are similar to those obtained in the classic, batch process. Thanks to the device, it is possible to obtain a repeatable product while reducing the workload. The produced gel beads were tested for water absorption and textural properties. The water absorption of the obtained gel capsules is strongly influenced by the pectin chain structure. Pectin beads obtained from currant pectins have a less hard structure and are more sensitive to deformation than those from apple pectin. Shorter and more branched chains of currant pectin than apple pectin form gels with a delicate structure, which strongly absorbs water, and unlike apple pectin gel, it disintegrates. The results show that the use of raw material obtained from different sources allows for obtaining products with various properties, using the same method; moreover, the used device is fully scalable and can be used in large scale.