Structure modification, functionality and interfacial properties of kidney bean (Phaseolus vulgaris L.) protein concentrate as affected by post-extraction treatments

The utilization of an ultrasonic mung bean protein-starch conjugate as a fat substitute in whipping cream

BACKGROUND

Amidst the rising trend of healthy eating, there is a surge in demand for low-fat food options. Within the realm of fat substitutes, modified proteins have shown the most effective ability to replace fat due to their nutritional attributes and functional properties. This study focused on the development of a fat substitute for low-fat whipping cream using the conjugate of ultrasonic mung bean protein and mung bean starch.

RESULTS

Our findings revealed that the emulsifying properties and solubility of the conjugates were significantly superior to those of mung bean protein alone (P < 0.05). This enhancement was attributed to a smaller particle size, depolymerization of protein molecules and increased total sulfhydryl content, especially the conjugate formed by 60 min ultrasonic mung bean protein and mung bean starch (UMBP60+MS). Incorporating UMBP60+MS as a fat substitute at a 10% ratio in the formulation of low-fat whipping cream resulted in a product with enhanced apparent viscosity, superior environmental stability, and commendable sensory characteristics. Moreover, the fat digestion rate was significantly reduced by 13.5% with the 10% substitution. This 10% substitution also endowed the whipping cream with the most desirable β'-type crystal morphology and the most stable three-dimensional network structure. An intimate encapsulation of fat globules by the conjugate was observed using cryogenic scanning electron microscopy.

CONCLUSION

The UMBP60+MS conjugate emerged as an effective fat substitute in whipping cream, providing significant contributions to addressing health concerns in the food industry. © 2024 Society of Chemical Industry.

Unveiling differential impact of heat and microwave extraction treatments on the structure, functionality, and digestibility of jack bean proteins extracted under varying extraction pH

The poor extractability and digestibility of jack beans restrict their application in food systems. Thermal treatment could be a processing tool to disrupt the compact conformation of the plant matrix and inactivate inherent antinutrients. Therefore, this research investigated the impact of conventional heat-aided (HA-) and microwave-aided (MA-) extraction treatments on the structure, functional properties, and digestibility of jack bean protein concentrate (JBPC) under varying extraction pH. The novelty brought by the present study is establishing the thermal treatment/extraction pH combinations for improving techno-functionalities and digestibility of JBPC. Heat (50 °C for 1 h) and sequential microwave power (400 W, 600 W, and 800 W for 5 min) at three extraction pH (9.0, 10.0, and 11.0) were studied. Upon increasing extraction pH, a significant decrease in the protein content, and β-Sheet structure was observed, in the order of pH 11.0 > 10.0 > 9.0. JBPC extracted using HA treatments displayed the highest contents of surface hydrophobicity (90.02) and sulfhydryl groups. In functional properties, MA-extracted JBPC under 400 W showed significantly improved solubility (93.45 %), emulsifying activity index (45.23 m2/g), and foaming capacity (141.70 %) when compared to other thermal treatments. The degree of hydrolysis result revealed that MA treatment improved the JBPC in vitro digestibility at a low power level of 400 W. These findings suggest that MA extraction treatment can improve the functional and nutritional properties of JBPC regardless of the extraction pH, and thus, expand the potential application in food systems.

Phosphate type dependent phosphorylation on the interfacial and emulsion stabilizing behaviors of goose liver protein: Perspective of protein charging

Elucidation on the emulsifying behaviors of goose liver protein (GLP) from interfacial perspective was scarce when protein charging was altered. This work aimed to elucidate the role of phosphorylation on the interfacial associative interaction and then emulsion stabilizing properties of GLP using three structurally relevant phosphates of sodium trimetaphosphate (STMP), sodium tripolyphosphate (STPP) and sodium pyrophosphate (TSPP). A monotonic increment of protein charging treated from STMP, STPP to TSPP caused progressively increased particle de-aggregation, surface hydrophobicity and structural flexibility of GLP. Compared with STMP and TSPP, STPP phosphorylation rendered the most strengthened interfacial equilibrium pressure (11.98 ± 0.24 mN/m) due to sufficient unfolding but moderated charging character conveyed. Desorption curve and interfacial protein microstructure indicated that STPP phosphorylation caused the highest interfacial connectivity between proteins adsorbed onto the same droplet, as was also verified by interfacial elastic modulus (10.3 ± 0.21 mN/m). STPP treated GLP also yielded lowest droplet size (8.16 ± 0.10 μm), flocculation (8.18%) and Turbiscan stability index (8.78 ± 0.36) of emulsion but most improved microrheological properties. Overall, phosphorylation functioned itself in fortifying the intradroplet protein-protein interaction but restraining the interdroplet aggregation, and STPP phosphorylation endowed the protein with most enhanced interfacial stabilization and emulsifying efficiency.

Extractions, Contents, Antioxidant Activities and Compositions of Free and Bound Phenols from Kidney Bean Seeds Represented by 'Yikeshu' Cultivar in Cold Region

To thoroughly understand the profile of phenolic phytochemicals in kidney bean seeds cultivated in a cold region, the extractions, contents, antioxidant activities, compositions of free and bound phenols in the seed coat and cotyledon, and also relevant color attributes, were investigated. The results indicated that ultrasound-assisted extraction was an efficient method for free phenols. The bound phenols in seed coat and cotyledon were released more efficiently by alkali-acid and acid-alkali sequential hydrolysis, respectively. Under the optimized extractions, total phenols (TPC), flavonoids (TFC), and anthocyanins (TAC) ranged in 7.81-32.89 mg GAE/g dw, 3.23-15.65 mg RE/g dw, and 0-0.21 mg CE/g dw in the whole seeds of the five common kidney beans. There was a big difference in phenolic distribution between red and white seeds. From whole seed, the phenols in the four red cultivars mainly existed in free state (78.84%) and seed coat (71.56%), while the phenols in the white 'Sark' divided equally between free (51.18%) and bound (48.82%) states and consisted chiefly in cotyledon (81.58%). The correlation analyses showed that the antioxidant activities were significantly and positively correlated with TPC and TFC. The phenolic attributes were closely associated with the color of the seed coat. Red seeds had higher total contents of phenols than white seeds. TAC had a positively significant correlation with redness. Brightness and yellowness showed a negatively significant correlation with TPC, TFC, and antioxidant capacities, which were necessarily linked with redness degree and spot in red seeds. The spotted red 'Yikeshu' with the most outstanding performance on phenolic attributes was selected to analyze phenolic compounds with UHPLC-QE-MS. Among the 85 identified phenolics, 2 phenolic acids and 10 flavonoids were dominant. The characteristic phenolics in free and bound states were screened in both seed coat and cotyledon, respectively. The available information on the phenolic profile may expand the utilization of kidney beans as a nutritional ingredient in the food industry.

Comparison of pH-induced protein-polyphenol self-assembly methods: Binding mechanism, structure, and functional characteristics

Herein, we used pH-shifted and pH-driven methods to assemble kidney-bean protein isolate (KPI) and luteolin (Lut) into a nanocomplex and subsequently investigated their binding mechanism, structure, and functional properties. Results showed that the nanocomplex prepared by the pH-driven method exhibited a better encapsulation effect and controlled release of Lut. Fluorescence spectroscopy and molecular docking analysis showed that the binding affinities under alkaline conditions were higher than those under acidic and neutral conditions. Various spectral techniques were used to determine the structural changes in the KPI-Lut nanocomplex, including the transformation of α-helices and β-sheets and alteration of specific amino acid microenvironments, which were more pronounced in the pH-driven nanocomplex. The structural changes in the nanocomplex further affected their surface hydrophobicity and thermal stability. Additionally, the combination of KPI and Lut significantly improved the antioxidant activity and α-glucosidase inhibitory ability of the resultant nanocomplexes, particularly the one prepared by the pH-driven method.

Phenolic structure dependent interaction onto modified goose liver protein enhanced by pH shifting: Modulations on protein interfacial and emulsifying properties

The appropriateness of animal by-product proteins as emulsifiers is barely explored compared to their meat counterparts. This paper focused on improving interfacial and emulsifying properties of modified goose liver protein using three structurally relevant polyphenols either enhanced by pH shifting (P-catechin, P-quercetin and P-rutin) or not (catechin, quercetin and rutin). Due to its high hydrophobicity and limited steric hindrance, quercetin was more sufficient to hydrophobically interact (ΔH > 0, ΔS > 0) with MGLP than catechin and rutin. Results showed that polyphenol interactive affinity was positively correlated to surface hydrophobicity but negatively to size and aggregation extent of MGLP. Interfacial pressure and dilatational elastic modulus implied that synergistic polyphenol interaction and pH shifting favored the interfacial adsorption and macromolecular association of MGLP, particularly for P-quercetin with the values reached to 19.9 ± 2.0 mN/m and 22.9 ± 1.2 mN/m, respectively. Emulsion stabilized by P-quercetin also maintained highest physical and oxidative stabilities regarding the lowest D [4,3] (3.78 ± 0.27 μm) and creaming index (8.38 ± 0.43 %), together with highest mono- (19.51 %) and polyunsaturated fatty acid content (29.39 %) during storage. Overall, chemical structure of polyphenols may be determining in fabricating MGLP-polyphenol complexes with improved emulsion stabilization efficiency.

Effects of protein concentration, ionic strength, and heat treatment on the interfacial and emulsifying properties of coconut (Cocos nucifera L.) globulins

This research aimed to investigate the effects of protein concentration (0.2 %-1.0 %), ionic strength (100-500 mM NaCl), and heat treatment (temperature: 80 and 90℃; time: 15 and 30 min) on the interfacial and emulsifying properties of coconut globulins (CG). When protein concentration was set at 0.2-0.6 %, the interfacial adsorption increased with the increasing of protein concentration. However, the lowest interfacial viscoelasticity was found when CG concentration was 0.6 %. When the protein concentration was higher than 0.6 %, the dilatational viscoelasticity increased with the increasing of protein concentration. The protein concentration showed positive effect on the emulsion stability of CG. The ionic strength showed positive effect on the interfacial adsorption but negative effects on the interfacial viscoelasticity and emulsion stability. Higher temperature and longer heating time brought worse interface behavior. The heated CG (90℃, 30 min) had the worst interfacial behavior but the best emulsion stability.

The Non-Nutritional Factor Types, Mechanisms of Action and Passivation Methods in Food Processing of Kidney Bean (Phaseolus vulgaris L.): A Systematic Review

Kidney beans (KBs), as a traditional edible legume, are an important food crop of high nutritional and economic value worldwide. KBs contain a full range of amino acids and a high proportion of essential amino acids, and are rich in carbohydrates as well as vitamins and minerals. However, KBs contain a variety of non-nutritional factors that impede the digestion and absorption of nutrients, disrupt normal metabolism and produce allergic reactions, which severely limit the exploitation of KBs and related products. Suppressing or removing the activity of non-nutritional factors through different processing methods can effectively improve the application value of KBs and expand the market prospect of their products. The aim of this review was to systematically summarize the main types of non-nutritional factors in KBs and their mechanisms of action, and to elucidate the effects of different food processing techniques on non-nutritional factors. The databases utilized for the research included Web of Science, PubMed, ScienceDirect and Scopus. We considered all original indexed studies written in English and published between 2012 and 2023. We also look forward to the future research direction of producing KB products with low non-nutritional factors, which will provide theoretical basis and foundation for the development of safer and healthier KB products.

Extraction Optimization, Functional and Thermal Properties of Protein from Cherimoya Seed as an Unexploited By-Product

Plant-based proteins are gaining in attraction compared with animal-based proteins due to their superior ethical profiles, growing concerns on the part of various organizations about animal health and welfare, and increased global greenhouse-gas emissions in meat production. In this study, the response surface methodology (RSM) using a Box-Behnken design (BBD) was applied to optimize the ultrasound-assisted alkaline extraction of cherimoya-seed proteins as valuable by-products. The effects of three pH, temperature, and time factors on the protein-extraction yield and protein content were investigated. The pH at 10.5 and temperature of 41.8 °C for 26.1 min were considered the optimal ultrasound-assisted alkaline-extraction conditions since they provided the maximum extraction yield (17.3%) and protein content (65.6%). An established extraction technique was employed to enhance the cherimoya-seed protein yield, purity, and functional properties. A thermogravimetric analysis (TGA) of the samples showed that the ultrasound-assisted alkaline extraction improved the thermal stability of the protein concentrate.

Effect of extraction methods on the properties of tilapia scale gelatins

Three types of tilapia scale gelatins (hot water-pretreated gelatin, HWG; acetic acid-pretreated gelatin, AAG; and pepsin enzyme-pretreated gelatin, PEG) were extracted and their gel strength, foaming properties, and emulsifying properties were analyzed. They had different gel strength values: AAG (370 ± 10 g Bloom) > HWG (320 ± 10 g Bloom) > PEG (280 ± 10 g Bloom). The creaming index values of tilapia scale gelatin-stabilized fish oil-loaded emulsions were dependent on gelatin type (HWG ≈ AAG > PEG) at low gelatin concentration (2 mg/mL), whereas they were similar and low (8-10 %) at high gelatin concentration (10 mg/mL). Extraction methods had no consistently significant effects on the gelatin foaming properties. In summary, tilapia scale gelatins had better gel strength and foaming properties and similar or even better emulsifying properties than mammalian gelatins. Therefore, tilapia scales could be a potential source of gelatins to replace mammalian gelatins.