Band 21, Heft 5

Lipase has emerged as a promising eco-friendly biocatalyst. However, its free-form application is limited by challenges, such as poor recovery and limited stability. Immobilization presents an effective strategy to overcome these limitations, thereby enhancing catalytic performance. Nevertheless, lipase immobilization is not obstacle-free either and necessitates comprehensive solutions. The development of novel immobilization techniques and matrix materials remains relatively underexplored. This review offers a comprehensive analysis of both traditional and advanced enzyme immobilization strategies, with a focus on how different carrier materials influence enzymatic properties and immobilization efficiency. By discussing the diverse industrial applications of immobilized lipases while also outlining potential research trajectories within this domain, this review aims to establish a robust theoretical framework for improving the performance of immobilized enzymes. Furthermore, innovative technologies such as 3D printing and membrane-based immobilization are expected to drive future advancements, thereby providing a strong theoretical foundation for the engineering of immobilized lipases.

In this work, the behaviors diffusion of sweeteners (sucrose, erythritol and stevioside) through the mucin layer were investigated based on the mucin-sweeteners interactions. Several techniques including fluorescence spectroscopy, rheological measurement, QCM-D and TEM were applied to investigate the interactions between the sweeteners and mucin at different pH values. The results point to the relatively fast diffusion behavior of sweeteners at pH 5.0 or pH 7.0, which was associated with the molecular weight of sweeteners and mucin-sweeteners interactions. The rheological measurement and QCM-D results indicated that hydrogen bonding and hydrophobic interactions may play an important role in mucin-sweeteners interactions. A homogeneous mucin network with large network pore size at pH 5.0 or pH 7.0 favored the diffusion of sweeteners through the mucin layer. Additionally, the relatively weak interactions between mucin layer and sweeteners at pH 5.0 or pH 7.0 contributes to the rapid penetration of sweeteners, enhancing the sweetness perception.

Radio frequency (RF) tempering, as a dielectric heating technology, is widely used in the tempering of frozen meat products, but non-uniformity heating is still a major obstacle to industrial applications. In this study, an RF tempering oven with a cooler and a temperature measuring program was used to investigate effects of cold air, different temperature difference thresholds (TDT), and different time-outs of RF power on the tempering uniformity for cubic- and cylindrical-shaped frozen chicken breasts. The results showed that the sample’s temperature increased with the tempering time, and the temperature at the corners and edges was higher than that at the center of sample during RF tempering. Additionally, the cold air could reduce the temperature at the corners and surfaces of the samples and improve the RF tempering uniformity. The temperature-time histories clearly showed wave shapes during intermittent RF tempering. After intermittent RF tempering, the heating uniformity index and average temperature values of the cubic sample followed the decreasing order: right surface > left surface > bottom surface > top surface. For the cylindrical sample, the top surface also had the best tempering uniformity and the lowest average temperature, and the right surface had the worst tempering uniformity and the highest average temperature. A smaller TDT and a longer time-out resulted in a lower temperature difference between the surface and the center of the samples, a lower tempering rate, and better tempering uniformity. With the optimal TDT and time-out, the best tempering uniformity was obtained after cold-air assisted intermittent RF tempering. The results of this research may provide useful information for improving the temperature distribution in the industrial RF tempering process.

This study investigated the quality characteristics of a plant-based functional beverage produced by fermenting almond milk with the probiotic strains Lactiplantibacillus plantarum (WLPL), Lactiplantibacillus pentosus (WLPE), and their combination (WLP). The dry matter, ash, protein, and fat contents of the fermented beverages were found to range from 6.55 % to 7.98 %, 0.20 % to 0.27 %, 3.27 % to 5.12 %, and 3.05 % to 3.91 %, respectively. Among the formulations, the WLP beverage exhibited the highest total phenolic content (758.8 mg GAE/L). The highest antioxidant activity was observed in the WLPE fermented beverage. Furthermore, the probiotic bacterial count remained above 8 log CFU/mL in all fermented samples for up to 14 days, indicating the sustained viability of the probiotic strains. After 14 days of storage, the beverage fermented with a combination of Lactiplantibacillus plantarum and Lactiplantibacillus pentosus was the most preferred by consumers, with notable differences in the color profiles of the various fermented beverages.

Lutein possesses various functional activities and is widely used in food and pharmaceuticals. However, lutein is sensitive to environmental factors, processing and storage conditions, resulting in low bioaccessibility. In this study, a nano-emulsion system based on soybean protein isolate (SPI) and guar gum (GG) was developed to enhance the stability and delivery efficiency of lutein. The lutein-loaded nano-emulsion was successfully prepared using corn oil as the oil phase and an SPI-GG complex as the aqueous phase via high-speed shearing combined with ultrasonication. The optimized nano-emulsion exhibited uniform particle size (225.73 ± 4.61 nm), high zeta potential (−43.87 ± 0.67 mV), and stability primarily maintained by hydrogen bonding and intermolecular interactions. In vitro simulated digestion experiments indicated that the nano-emulsion significantly improved free fatty acid (FFA) release (80.00 %) and lutein bioaccessibility (78.71 %), outperforming the water–oil mixture system (48.24 %). Environmental stability tests demonstrated that the nano-emulsion remained stable under weak acidic to alkaline conditions (pH 6–12), low salt concentrations (20–80 mM Na + ), potassium sorbate (0.2–0.8 g/kg), and sucrose (7–9 g/mL). Storage stability analysis revealed that the nano-emulsion effectively delayed lutein degradation for 14 days under dark conditions at 4 °C. This study provides theoretical support for the development of efficient delivery systems for hydrophobic bioactive compounds, with potential applications in functional foods and oral drug delivery systems.

The present study aims to develop polyphenol-enriched low GI bread using phytochemical rich karonda powder. The refined wheat flour was supplemented with ripe karonda powder (RKP) at 1.5 %, 3.0 %, 4.0 %, and 6.0 % level. The prepared formulations were evaluated for their chemical, physical, texture, sensory properties and starch digestibility. Properties like loaf height, specific volume, and bake loss decreased with increase in RKP incorporation. Specifically, loaf height and volume reduced from 8.07 cm and 562 cc (control) to 5.52 cm and 355.67 cc at 6 % RKP incorporation. Total phenolic content increased from 25.56 mg GAE/100 g in control bread to 66.94 mg GAE/100 g at 6 % RKP incorporation, showing a 162 % increase. Antioxidant activity, measured by DPPH inhibition, increased from 12.16 % in control bread to 21.91 % in 6 % RKP-enriched bread. Texture analysis indicated that as the concentration of RKP increased, the bread exhibited increased hardness due to the dilution of the gluten network. Additionally, incorporating RKP increased the redness (a*) and reduced the lightness (L*) value in bread, attributable to the anthocyanin content in RKP. Sensory evaluation results suggested that bread containing 3 % RKP was the most acceptable, with flavour and texture scores comparable to the control. Furthermore, in vitro starch digestibility and predicted glycemic index (pGI) analysis revealed that incorporating RKP at 1.5 % and 3.0 % significantly lowered the pGI by 10.63 % and 20 %, respectively, compared to control bread. This study will be helpful for diabetic patients to manage their blood glucose levels by incorporating polyphenols in their diet.