Esterification of black bean anthocyanins with unsaturated oleic acid, and application characteristics of the product.

Esterification of anthocyanins with saturated fatty acids have been widely investigated, while that with unsaturated fatty acids is little understood. In this study, crude extract (purity âˆ¼ 35 %) of cyanidin-3-O-glucoside (C3G) from black bean seed coat was utilized as reaction substrate, and enzymatically acylated with unsaturated fatty acid (oleic acid). Optimization of various reaction parameters finally resulted in the highest acylation rate of 54.3 %. HPLC-MS/MS and NMR analyses elucidated the structure of cyanidin-3-O-glucoside-oleic acid ester (C3G-OA) to be cyanidin-3-O-(6″-octadecene)-glucoside. Introduction of oleic acid into C3G improved the lipophilicity, antioxidant ability, and antibacterial activity. Further, the color and substance stability analyses showed that the susceptibility of C3G and C3G-OA to different thermal, peroxidative, and illuminant treatments were highly pH dependent, which suggested individual application guidelines. Moreover, C3G-OA showed lower toxicity to normal cell (QSG-7701) and better inhibitory effect on the proliferation of HepG2 cells than C3G, which indicated its potential anti-tumor bioactivity.

Non-starch polysaccharides from kidney beans: comprehensive insight into their extraction, structure and physicochemical and nutritional properties.

Kidney beans (Phaseolus vulgaris L.) are an important legume source of carbohydrates, proteins, and bioactive molecules and thus have attracted increasing attention for their high nutritional value and sustainability. Non-starch polysaccharides (NSPs) in kidney beans account for a high proportion and have a significant impact on their biological functions. Herein, we critically update the information on kidney bean varieties and factors that influence the physicochemical properties of carbohydrates, proteins, and phenolic compounds. Furthermore, their extraction methods, structural characteristics, and health regulatory effects, such as the regulation of intestinal health and anti-obesity and anti-diabetic effects, are also summarized. This review will provide suggestions for further investigation of the structure of kidney bean NSPs, their relationships with biological functions, and the development of NSPs as novel plant carbohydrate resources.

Common Beans as a Source of Amino Acids and Cofactors for Collagen Biosynthesis.

Common beans (Phaseolus vulgaris L.) are widely consumed in diets all over the world and have a significant impact on human health. Proteins, vitamins, minerals, phytochemicals, and other micro- and macronutrients are abundant in these legumes. On the other hand, collagens, the most important constituent of extracellular matrices, account for approximately 25-30 percent of the overall total protein composition within the human body. Hence, the presence of amino acids and other dietary components, including glycine, proline, and lysine, which are constituents of the primary structure of the protein, is required for collagen formation. In this particular context, protein quality is associated with the availability of macronutrients such as the essential amino acid lysine, which can be acquired from meals containing beans. Lysine plays a critical role in the process of post-translational modifications facilitated with enzymes lysyl hydroxylase and lysyl oxidase, which are directly involved in the synthesis and maturation of collagens. Furthermore, collagen biogenesis is influenced by the cellular redox state, which includes important minerals and bioactive chemicals such as iron, copper, and certain quinone cofactors. This study provides a novel perspective on the significant macro- and micronutrients present in Phaseolus vulgaris L., as well as explores the potential application of amino acids and cofactors derived from this legume in the production of collagens and bioavailability. The utilization of macro- and micronutrients obtained from Phaseolus vulgaris L. as a protein source, minerals, and natural bioactive compounds could optimize the capacity to promote the development and durability of collagen macromolecules within the human body.

Texture classification and in situ cation measurements by SEM-EDX provide detailed quantitative insights into cell wall cation interaction changes during ageing, soaking, and cooking of red kidney beans.

Hard-to-cook (HTC) is a textural defect that delays the softening of common bean seeds during cooking. While this defect is commonly associated with conventionally stored beans, soaking/cooking of beans in CaCl2 solutions or sodium acetate buffer can also prolong the cooking time of beans due to formation of Ca2+ crosslinked pectin retarding bean softening during cooking. In this study, the role of the cell wall-bound Mg2+/Ca2+ content and the degree of pectin methyl esterification (DM) was quantified, as important factors for bean texture-related changes stipulated in the pectin-cation-phytate hypothesis, the most plausible hypothesis of HTC development. Evaluation of texture changes during cooking of conventionally aged beans (35 °C and 83% RH for up to 20 weeks), beans soaked/cooked in CaCl2 solutions (0.01 to 0.1 M) or soaked in 0.1 M sodium acetate buffer (pH 4.4) revealed large bean-to-bean variations. Therefore a texture-based classification approach was used to better capture the relation between texture characteristics and cell wall polymer, in particular pectin, related changes. While cell wall-bound Ca2+ and pectin DM did not change/were not related to the texture variation during cooking of fresh beans, increased cell wall-bound Ca2+ and decreased pectin DM were associated with prolonged conventional storage of beans and their texture changes during subsequent cooking (due to pectin cross linking, retarding its solubilization during cooking). Exogenously added Ca2+ from pre-treating beans in CaCl2 solutions promoted to a great extent the cell wall-bound Ca2+ during soaking but even more so during cooking, complementing the harder texture associated with these beans during cooking (compared to conventionally stored and fresh beans). Similarly, free Ca2+ endogenously generated by phytase-catalysed phytate hydrolysis (beans treated by acetate buffer) promoted crosslinking of pectin by Ca2+ (cell wall-bound Ca2+), delaying softening of beans during cooking.

Dry beans (Phaseolus vulgaris L.) modulate the kinetics of lipid digestion in vitro: Impact of the bean matrix and processing.

The lipid-lowering effect of dry beans and their impact on lipid and cholesterol metabolism have been established. This study investigates the underlying mechanisms of this effect and explore how the structural integrity of processed beans influences their ability to modulate lipolysis using the INFOGEST static in vitro digestion model. Dietary fiber (DF) fractions were found to decrease lipolysis by increasing the digesta viscosity, leading to depletion-flocculation and/or coalescence of lipid droplets. Bean flours exhibited a more pronounced reduction in lipolysis compared to DF. Furthermore, different levels of bean structural integrity showed varying effects on modulating lipolysis, with medium-sized bean particles demonstrating a stronger reduction. Hydrothermal treatment compromised the ability of beans to modulate lipid digestion, while hydrostatic-pressure treatment (600 MPa/5min) enhanced the effect. These findings highlight that the lipid-lowering effect of beans is not solely attributed to DF but also to the overall bean matrix, which can be manipulated through processing techniques.

Effect of bio-chemical changes due to conventional ageing or chemical soaking on the texture changes of common beans during cooking.

To establish the HTC defect development, the cooking kinetics of seeds of ten bean accessions (belonging to seven common bean market classes), fresh and conventionally aged (35 °C, 83% RH, 3 months) were compared to those obtained after soaking in specific salt solutions (in 0.1 M sodium acetate buffer at pH 4.4, 41 °C for 12 h, or 0.01 M CaCl2 at pH 6.2, 25 °C for 16 h and subsequently cooking in CaCl2 solution, or deionised water). The extent of phytate (inositol hexaphosphate, IP6) hydrolysis was evaluated to better understand the role of endogenous Ca2+ in the changes of the bean cooking kinetics. A significant decrease in the IP6 content was observed after conventional ageing and after soaking in a sodium acetate solution suggesting phytate hydrolysis (release of endogenous Ca2+). These changes were accompanied by an increase in the cooking time of the beans. Smaller changes in cooking times after soaking in a sodium acetate solution (compared to conventionally aged beans) was attributed to a lower ionisation level of the COOH groups in pectin (pH 4.4, being close to pKa value of pectin) limiting pectin Ca2+ cross-linking. In beans soaked in a CaCl2 solution, the uptake of exogenous cations increased the cooking times (with no IP6 hydrolysis). The change in cooking time of conventionally aged beans was strongly correlated with the extent of IP6 hydrolysis, although two groups of beans with low or high IP6 hydrolysis were distinguished. Comparable trends were observed when soaking in CaCl2 solution (r = 0.67, p = 0.14 or r = 0.97, p = 0.03 for two groups of beans with softer or harder texture during cooking). Therefore a test based on the Ca2+ sensitivity of the cooking times, implemented through a Ca2+ soaking experiment followed by cooking can be used as an accelerated test to predict susceptibility to HTC defect development during conventional ageing. On the other hand, a sodium acetate soaking experiment can be used to predict IP6 hydrolysis of conventionally aged bean accessions and changes of cooking times for these bean accessions (with exception of yellow bean-KATB1).

Application of state diagrams to understand the nature and kinetics of (bio)chemical reactions in dry common bean seeds: A scientific guide to establish suitable postharvest storage conditions.

Storage is a fundamental part of the common bean postharvest chain that ensures a steady supply of safe and nutritious beans of acceptable cooking quality to the consumers. Although it is known that extrinsic factors of temperature and relative humidity (influencing the bean moisture content) control the cooking quality deterioration of beans during storage, the precise interactions among these extrinsic factors and the physical state of the bean matrix in influencing the rate of quality deteriorative reactions is poorly understood. Understanding the types and kinetics of (bio)chemical reactions that influence the cooking quality of beans during storage is important in establishing suitable storage conditions to ensure quality stability. In this review, we integrate the current insights on glass transition phenomena and its significance in describing the kinetics of (bio)chemical reactions that influence the cooking quality changes during storage of common beans. Furthermore, a storage stability map based on the glass transition temperature of beans as well as kinetics of the main (bio)chemical reactions linked to cooking quality deterioration during storage was designed as a guide for determining appropriate storage conditions to ensure cooking quality stability.

Metabolomic analysis reveals stress tolerance mechanisms in common bean (Phaseolus vulgaris L.) related to treatment with a biostimulant obtained from Corynebacterium glutamicum.

Microbial biostimulants have emerged as a sustainable alternative to increase the productivity and quality of important crops. Despite this, the effects of the treatment on plant metabolism are poorly understood. Thus, this study investigated the metabolic response of common bean (Phaseolus vulgaris) related to the treatment with a biostimulant obtained from the extract of Corynebacterium glutamicum that showed positive effects on the development, growth, and yield of crops previously. By untargeted metabolomic analysis using UHPLC-MS/MS, plants and seeds were subjected to treatment with the biostimulant. Under ideal growth conditions, the plants treated exhibited higher concentration levels of glutamic acid, nicotiflorin and glycosylated lipids derived from linolenic acid. The foliar application of the biostimulant under water stress conditions increased the chlorophyll content by 17% and induced the accumulation of flavonols, mainly quercetin derivatives. Also, germination seed assays exhibited longer radicle lengths for seeds treated compared to the untreated control even in the absence of light (13-18% increase, p-value <0.05). Metabolomic analysis of the seeds indicated changes in concentration levels of amino acids (tryptophan, phenylalanine, tyrosine, glutamine, and arginine) and their derivatives. The results point out the enhancement of abiotic stress tolerance and the metabolic processes triggered in this crop associated with the treatment with the biostimulant, giving the first insights into stress tolerance mechanisms in P. vulgaris.

A validated LC-MS/MS method for quantitative determination of L-dopa in Fagioli di Sarconi beans (Phaseolus vulgaris L.).

An analytical method based on ultrasound assisted extraction (UAE) and liquid chromatography coupled to electrospray tandem mass spectrometry (LC-ESI/MS/MS) was validated and applied for determining L-dopa in four ecotypes of Fagioli di Sarconi beans (Phaseolus vulgaris L.), marked with the European label PGI (Protected Geographical Indication). The selectivity of the proposed method was ensured by the specific fragmentation of the analyte. Simple isocratic chromatographic conditions and mass spectrometric detection in multiple reaction monitoring (MRM) acquisition mode were used for sensitive quantification. The LC-ESI/MS/MS method was validated within a linear range of 0.001-5.000 µg/mL. Values of 0.4 and 1.1 ng/mL were obtained for the limits of detection and quantification, respectively. The repeatability, inter-day precision, and recovery values ranges were 0.6%-4.5%, 5.4%-9.9%, and 83%-93%, respectively. Fresh and dried beans, as well as pods, cultivated exclusively with organic methods avoiding any synthetic fertilizers and pesticides were analyzed showing an L-dopa content ranging from 0.020 ± 0.005 to 2.34 ± 0.05 µg/g dry weight.

Genetic variation in a tepary bean (Phaseolus acutifolius A. Gray) diversity panel reveals loci associated with biotic stress resistance.

Tepary bean (Phaseolus acutifolius A. Gray), indigenous to the arid climates of northern Mexico and the Southwest United States, diverged from common bean (Phaseolus vulgaris L.), approximately 2 million years ago and exhibits a wide range of resistance to biotic stressors. The tepary genome is highly syntenic to the common bean genome providing a foundation for discovery and breeding of agronomic traits between these two crop species. Although a limited number of adaptive traits from tepary bean have been introgressed into common bean, hybridization barriers between these two species required the development of bridging lines to alleviate this barrier. Thus, to fully utilize the extant tepary bean germplasm as both a crop and as a donor of adaptive traits, we developed a diversity panel of 422 cultivated, weedy, and wild tepary bean accessions which were then genotyped and phenotyped to enable population genetic analyses and genome-wide association studies for their response to a range of biotic stressors. Population structure analyses of the panel revealed eight subpopulations and the differentiation of botanical varieties within P. acutifolius. Genome-wide association studies revealed loci and candidate genes underlying biotic stress resistance including quantitative trait loci for resistance to weevils, common bacterial blight, Fusarium wilt, and bean common mosaic necrosis virus that can be harnessed not only for tepary bean but also common bean improvement.

Black and pinto beans (Phaseolus vulgaris L.) unique mexican varieties exhibit antioxidant and anti-inflammatory potential.

Oxidative stress and inflammation play a key role in diverse pathological conditions such as cancer and metabolic disorders. The objective of this study was to determine the antioxidant and anti-inflammatory potentials of crude extract (CE) and phenolic-enriched extract (PHE) obtained from the seed coats (SCs) of black bean (BB) and pinto bean (PB) varieties. Delphinidin-3-O-glucoside (46 mg/g SC), malvidin-3-O-glucoside (29.9 mg/g SC), and petunidin-3-O-glucoside (7.5 mg/g SC) were found in major concentrations in the PHE-BB. Pelargonidin (0.53 mg/g SC) was only identified in the PHE-PB. PHE from both varieties showed antioxidant and radical scavenging capacities, with strong correlations associated with total phenolic content (TPC). Polyphenolics, including catechin, myricetin, kaempferol, quercetin, and isorhamnetin glucosides, were identified in the extracts. In terms of the anti-inflammatory potentials, PHE-PB had an IC50 of 10.5 µg dry extract/mL (µg DE/mL) for cyclooxygenase-2 (COX-2) inhibition. The inhibition values for cyclooxygenase-1 (COX-1) ranged from 118.1 to 162.7 µg DE/mL. Regarding inducible nitric oxide synthase (iNOS) inhibition, PHE-BB had an IC50 of 62.6 µg DE/mL. As determined via in silico analysis, pelargonidin showed binding affinities of -7.8 and -8.5 kcal/mol for COX-1 and iNOS, respectively, and catechin had a value of -8.3 kcal/mol for COX-2. Phenolic-enriched extracts from seed coats of black and pinto beans showed good antioxidant and anti-inflammatory potential that warrants in vitro and in vivo studies.

Non-conventional starches isolated from agronomic-improved beans (Phaseolus vulgaris L.): a study of their structure and physicochemical properties.

BACKGROUND: Non-conventional starch sources are promising alternative food ingredients. Different bean varieties with agronomic improvements are constantly being developed and cultivated in the Northwestern Argentinean region (NOA) to increase yields and obtain high-quality seeds. However, the main attributes of their starches have not been studied. In this work, starches from four agronomic-improved bean cultivars were isolated and their structure and physicochemical properties were evaluated. RESULTS: High-purity starches were obtained, as shown by their low protein and ash content. Starch granules presented smooth surfaces with spherical to oval shapes, with a marked 'Maltese cross' and heterogeneous sizes. Their amylose content revealed a mean value of 318 g kg-1 and all presented resistant > slowly digestible > rapidly digestible starch fractions. Their Fourier transform infrared spectra were similar and X-ray diffraction analysis showed a CA -type pattern in all cases despite their different sources. Among thermal properties, Escarlata starch showed the lowest gelatinization peak temperature (69.5 °C) and Anahí starch the highest (71.3 °C). Starch pasting temperature varied from 74.6 to 76.9 °C, whereas peak viscosity and final viscosity showed a similar tendency, with Leales B30 < Anahí < Escarlata < Cegro 99/11-2 and Leales B30 < Anahí = Escarlata < Cegro 99/11-2, respectively. CONCLUSION: This study provides the basis for a better understanding of the characteristics of agronomic-improved NOA bean starches, enabling their use in product formulation as an alternative to starches from conventional sources. © 2023 Society of Chemical Industry.

A Natural Glucan from Black Bean Inhibits Cancer Cell Proliferation via PI3K-Akt and MAPK Pathway.

A natural α-1,6-glucan named BBWPW was identified from black beans. Cell viability assay showed that BBWPW inhibited the proliferation of different cancer cells, especially HeLa cells. Flow cytometry analysis indicated that BBWPW suppressed the HeLa cell cycle in the G2/M phase. Consistently, RT-PCR experiments displayed that BBWPW significantly impacts the expression of four marker genes related to the G2/M phase, including p21, CDK1, Cyclin B1, and Survivin. To explore the molecular mechanism of BBWPW to induce cell cycle arrest, a transcriptome-based target inference approach was utilized to predict the potential upstream pathways of BBWPW and it was found that the PI3K-Akt and MAPK signal pathways had the potential to mediate the effects of BBWPW on the cell cycle. Further experimental tests confirmed that BBWPW increased the expression of BAD and AKT and decreased the expression of mTOR and MKK3. These results suggested that BBWPW could regulate the PI3K-Akt and MAPK pathways to induce cell cycle arrest and ultimately inhibit the proliferation of HeLa cells, providing the potential of the black bean glucan to be a natural anticancer drug.

Solid-state fermentation alters the fate of red kidney bean protein during buccal and gastrointestinal digestion: Relationship with cotyledon cell wall integrity.

The relationship between legume cotyledon cell wall and macromolecular nutrient digestibility has attracted increased attention. In this study, the effect of solid-state fermentation by Rhizopus oligosporus RT-3 on the digestibility of red kidney bean protein and its relationship with cotyledon cell integrity were investigated. Buccal digestion and gastrointestinal digestion were performed to compare the fate of protein between unfermented (F0) and fermented samples. Results showed a remarkable disruption in cotyledon cell integrity at the late fermentation period, and it was accompanied by a possible migration/degradation of protein matrix. Buccal and gastrointestinal digestion barely affected cell wall integrity at F0 but notably disintegrated cell morphology at 29 h of fermentation (F29). As this fermentation time, gastrointestinal digestion resulted in higher contents of soluble proteins, peptides, and free amino acids by 1.4-, 1.8-, and 2.5-fold, respectively. Therefore, solid-state fermentation facilitated the structural breakdown of cotyledon cell walls, thereby further improving protein digestibility.

Comparative study, homology modelling and molecular docking with cancer associated glycans of two non-fetuin-binding Tepary bean lectins.

We present the purification and characterization of the two most abundant isoforms of lectins isolated from Tepary bean (Phaseolus acutifolius) seeds, which have been shown to differentially affect the survival of different cancer cells. They were separated by concanavalin A-affinity chromatography. After purification, to release the N-glycans, they were digested with the endoglycosidases PNGase and Glycanase A. Fractions resulted from the hydrolysis products were analyzed to determine their carbohydrate composition. Mass spectrometry data indicated that both isoforms contained high mannose glycans being mannose 6 the most abundant form. Furthermore, based on sequence Ans-X-Ser/Thr, where X is any amino acid except proline, a glycosylation site was determined on asparagine 36. When their metal requirement to preserve their biological activity was determined, the lectins showed differences. While lectin A (LA) agglutination activity was best in the presence of magnesium, lectin B (LB) was best with calcium. Additionally, only LA exhibited affinity to human type-A erythrocytes. Although both lectins showed small differences in their properties, an identical structure-model for both lectins was generated by the homology modelling process. Also, the analysis of ligand binding sites and in silico glycosylation were achieved. Molecular docking with colon adenocarcinoma associated-N-glycans revealed some highly possible interactions and, on the other hand, that N-glycan interaction zones of Tepary bean lectins is not restricted to the carbohydrate binding domain but to an extended part of their surface, which could lead new strategies to explain their biological activity.

Phytate and mineral profile evolutions to explain the textural hardening of common beans (Phaseolus vulgaris L.) during postharvest storage and soaking: Insights obtained through a texture-based classification approach.

During adverse postharvest storage of Red haricot beans, the inositol phosphate content, particularly InsP6, decreased significantly, along with a significant increase in InsP5. Using a texture-based classification approach, the InsP6 content in cotyledons was shown an indicator for the extent of hard-to-cook (HTC) development during bean aging. This textural defect development was predominated by storage-induced InsP6 degradation, rather than phytate interconversions during soaking. Ca cations, released during storage, did not leach out significantly during subsequent soaking, suggesting that they were bound with the cell wall pectin in cotyledons, while Mg cations were mostly leached out into the soaking water due to their weak binding capacity to the pectin, and the cell membrane damages developed during HTC. Results obtained herein provide evidence for the pectin-cation-phytate mechanism in textural hardening (and its distribution after cooking) of common beans, and call for a more detailed Ca-relocation study during postharvest storage, soaking and cooking.

Common Bean Seeds Obtained by Plant Water Restriction Ameliorates Obesity-Associated Cardiovascular Risk and Insulin Resistance.

The inclusion of beans in the diet has been recommended for obesity control. However, its beneficial effect varies depending on agroclimatic factors acting during plant development. The antiobesogenic capacity of Dalia bean (DB) seeds obtained by water restriction (WR) during the vegetative or reproductive stage of plant growth (50/100 and 100/50% of soil moisture in vegetative/reproductive stage, respectively), during the whole cycle (50/50), and well-watered plants (100/100) was researched. After phytochemical characterization, harvested beans from each experimental unit were pooled among treatments, based on a multivariate canonical discriminant analysis considering concentration of non-digestible carbohydrates (total, soluble and insoluble dietary fiber and resistant starch), phenolic compounds (total phenols, flavonoids, anthocyanins and condensed tannins) and total saponins, which showed no differences among replicas of each treatment. Obesity was induced in rats (UAZ-2015-36851) with a high fat diet (HFD) for four months. Afterwards, rats were fed with the HFD supplemented with 20% of cooked DB for three months. During treatment, 100/50 beans, improved blood triglycerides, cholesterol, and glucose, and alleviated early insulin resistance (IR) related to inhibition of lipase, α-amylase and -glucosidase activity. After sacrifice, a hypolipidemic capacity and atherogenic risk reduction was observed, especially from the 100/50 treatment, suggesting that intake of DB obtained from WR may prevent IR and dyslipidemia.

Alpha-cadinol as a potential ACE-inhibitory volatile compound identified from Phaseolus vulgaris L. through in vitro and in silico analysis.

Hypertension is a major risk factor of cardiovascular diseases, which is mainly caused due to over activation of renin-angiotensin system. The angiotensin converting enzyme (ACE), which is involved in formation of angiotensin II from angiotensin I, causes the blood vessels to constrict, in turn leading to hypertension. The current study was initiated to understand the role of bioactive volatile compounds from Phaseolus vulgaris L. (common bean), in ACE enzyme inhibition. Beans aqueous extract (BAE) showed maximum ACE inhibition of 88.4 ± 0.8% in comparison to other commonly consumed vegetables like spinach and garlic. The head space gas chromatography-mass spectrometry analysis showed the presence of a number of terpenes and terpenoids, which were present prominently in BAE. In silico molecular docking studies indicated that among the other volatile compounds, alpha-cadinol (-7.27 kcal/mol) and ar-tumerone (-6.44 kcal/mol) have the maximum binding affinity with the active site of ACE, as compared to that of captopril (-6.41 kcal/mol). The molecular dynamic simulation in biological environment, showed that alpha-cadinol forms a stable complex with ACE, with average binding energy of -42 kJ/mol. The ACE:alpha-cadinol complex was found to be stable mainly due to the hydrophobic interactions of alpha-cadinol with active site residues (Tyr523 and Phe457) of ACE. The in silico drug-likeness analysis showed that alpha-cadinol is appropriate for human system with no predicted hepatotoxicity or mutagenicity (AMES toxicity).Communicated by Ramaswamy H. Sarma.

Tracking the driving forces for the unfolding and folding of kidney bean protein isolates: Revealing mechanisms of dynamic changes in structure and function.

Tracking the dynamic changes in the structure of kidney bean protein isolate (KPI) during extreme pH-shifting can reveal the different mechanisms that drive the unfolding and refolding of the protein from a conformational perspective and elucidate the relationship between its structure and function. The secondary and tertiary structures of KPI were analyzed using multispectral techniques. The results showed that acidic-shifting affected the hydrophobic interactions of KPI molecules, whereas alkaline-shifting affected hydrogen bonding and electrostatic interactions of the molecules. Therefore, alkaline-shifting was more likely to affect KPI conformation. SEM revealed that pH-shifting transformed the sheet structure of KPI into spheres and rods; moreover, it improved the surface hydrophobicity, thermal stability, emulsification, foaming, and antioxidant properties of KPI. In summary, each pH-shifting stage disrupts a different intermolecular force, resulting in protein conformational diversity, while structural changes further affect function. Therefore, pH-shifting treatment broadens the applications scope of KPI in the food industry.

TXRF spectral information enhanced by multivariate analysis: A new strategy for food fingerprint.

The increased costumers' request of safe and high-quality food products makes food traceability a priority for frauds identification and quality certification. Elemental profiling is one of the strategies used for food traceability, and TXRF spectroscopy is widely used in food analysis even if its potentialities have not been fully investigated. In this work, a new method for food traceability using directly TXRF spectra coupled with multivariate analyses, was tested. Twenty-four different beans' genotypes (Phaseolus vulgaris L.) grown onto two different sites have been studied. After the development of the method for beans' analysis, TXRF spectra were collected and processed with PCA combined with SNV and GLSW filter obtaining a perfect clustering of the seeds according to their geographical origin. Finally, using PLS-DA, beans were correctly classified demonstrating that TXRF spectra can be successfully used as fingerprint for food/seed traceability and that elemental quantification procedure is not necessary to this aim.