The major proteins of lupin seed: Characterisation and molecular properties for use as functional and nutraceutical ingredients

Surface activity of Lupinus angustifolius (blue lupine) seed extracts

Surface tension (γeq) of the seed extracts of four lupine cultivars showed values in the range 44.9-46.4 mN/m. The surface compression elasticity (E') of the adsorbed layers and foaming capacity (FC) also showed similar values (E' ∼ 30 mN/m, FC ∼ 100%). The effect of defatting prior to extraction at pH 8.5 depends on the solvent employed - hexane and dichloromethane improved the subsequent protein extraction yield, while ethanol reduced it. The effect of defatting on surface tension could be positive (for hexane and ethanol) or negative (for dichloromethane). Generally, defatting improved the surface compression rheological and foaming parameters. On the other hand, fractionation of the extracts obtained at pH 8.5 from hexane-defatted seeds did not improve significantly the surface activity parameters. Some improvement with respect to the unfractionated extracts was observed only for the extracts of undefatted seeds. γeq, E', E" and FC isotherms confirm the surfactant-like behavior of the lupine seed extracts.

Proteome reorganization and amino acid metabolism during germination and seedling establishment in Lupinus albus

During germination plants rely entirely on their seed storage compounds to provide energy and precursors for the synthesis of macromolecular structures until the seedling has emerged from the soil and photosynthesis can be established. Lupin seeds use proteins as their major storage compounds, accounting for up to 40% of the seed dry weight. Lupins are therefore a valuable complement to soy as a source of plant protein for human and animal nutrition. The aim of this study was to elucidate how storage protein metabolism is coordinated with other metabolic processes to meet the requirements of the growing seedling. In a quantitative approach, we analysed seedling growth, as well as alterations in biomass composition, the proteome, and metabolite profiles during germination and seedling establishment in Lupinus albus. The reallocation of nitrogen resources from seed storage proteins to functional seed proteins was mapped based on a manually curated functional protein annotation database. Although classified as a protein crop, Lupinus albus does not use amino acids as a primary substrate for energy metabolism during germination. However, fatty acid and amino acid metabolism may be integrated at the level of malate synthase to combine stored carbon from lipids and proteins into gluconeogenesis.

Pereira C, Mafra I, Costa J. γ-Conglutin Immunoreactivity Is Differently Affected by Thermal Treatment and Gastrointestinal Digestion in Lupine Species

Lupine is a legume commonly used in human diet as a functional food due to its high nutritional content and important technological properties. However, its consumption can lead to the manifestation of adverse immunological reactions, posing significant health issues in sensitized/allergic patients. This work aims to investigate the effect of food processing combined with simulated gastrointestinal (GI) digestion on the immunoreactivity of lupine γ-conglutin. Model foods of wheat pasta containing 35% of lupine flour (Lupinus albus, L. luteus, and L. angustifolius) were prepared and submitted to a boiling process. The proteins were extracted and their profiles characterized by SDS-PAGE. Simulated GI digestion was performed on thermally treated pasta using the INFOGEST harmonized digestion protocol 2.0. The IgG binding capacity of γ-conglutin was assessed by immunoblotting in non-reducing conditions and indirect ELISA with specific antibodies. Results demonstrate that the boiling treatment affected the immunoreactivity of the three lupine species differently. Simulated GI digestion led to extensive destruction of the protein structure, more significant in the intestinal phase, reducing but not abolishing the IgG affinity to γ-conglutin and its potential presentation to immunocompetent cells. This information can offer valuable insights to the food industry for developing food formulations with reduced allergenic properties.

Addressing astringency of grape seed extract by covalent conjugation with lupin protein

Astringency of phenolic-rich foods is a key tactile perception responsible for acceptability/rejection of plant extracts as ingredients in formulations. Covalent conjugation of phenolic extracts with plant proteins might be a promising strategy to control astringency, but suffers from a lack of mechanistic understanding from the lubrication point of view. To shed light on this, this ex vivo study evaluated the effect of conjugation of a phenolic grape seed extract (GSE) with legume protein (lupin, LP) on tribological and surface adsorption performance of GSE in the absence and presence of human saliva (ex vivo). Tribological results confirmed GSE had an inferior lubrication capacity as compared to LP. The lubrication performance of LP-GSE dispersions was comparable to their corresponding LP dispersion (p > 0.05) when covalently conjugated with LP (LP-GSE) with increasing LP:GSE ratio up to 1:0.04 w/w and at a specific degree of conjugation (DC: 2%). Tribological and surface adsorption measurements confirmed the tendency of GSE to interact with human saliva (ex vivo, n = 17 subjects), impairing the lubricity of salivary films. The covalent bonding of LP to GSE hindered GSE's interaction with human saliva, implying the potential influence of covalent conjugation on attenuating astringency. LP appeared to compete with human saliva for surface adsorption and governed the lubrication behaviour in LP-GSE dispersions. Findings from this study provide valuable knowledge to guide the rational design of sustainable, functional foods using conjugation of phenolics with plant proteins to incorporate larger proportions of health-promoting phenolics while controlling astringency, which needs validation by sensory trials.

Biochemical Characterization of the Seed Quality of a Collection of White Lupin Landraces from Southern Italy

Lupin species provide essential nutrients and bioactive compounds. Within pulses, they have one of the highest contents of proteins and fibers and are among the poorest in carbohydrates. The Mediterranean region is an important cradle area of the origin and domestication of cultivated white lupin (Lupinus albus L.). In this work, we present the characterization of 19 white lupin landraces collected from several sites in southern Italy, characterized by different pedoclimatic conditions. The protein contents and electrophoretic patterns, total polyphenols, phytic acid, lipids and phosphorous content, and reducing and anti-tryptic activities have been determined for each landrace. The relationships of the compositional characteristics, the area of origin of landraces and between compositional characteristics and thermo-pluviometric trends that occurred in the genotype comparison field during the two-year period between 2019 and 2020 are compared and discussed. From a nutritional point of view, some of the analyzed landraces differ from the commercial reference. The panel of molecular analyses performed can help in building an identity card for the grain to rapidly identify those varieties with the desired characteristics.

Influence of Roasting Temperature on the Detectability of Potentially Allergenic Lupin by SDS-PAGE, ELISAs, LC-MS/MS, and Real-Time PCR

Seeds of "sweet lupins" have been playing an increasing role in the food industry. Lupin proteins may be used for producing a variety of foods, including pasta, bread, cookies, dairy products, and coffee substitutes. In a small percentage of the population, lupin consumption may elicit allergic reactions, either due to primary sensitization to lupin or due to cross-allergy with other legumes. Thus, lupin has to be declared on commercial food products according to EU food regulations. In this study, we investigated the influence of roasting seeds of the L. angustifolius cultivar "Boregine" on the detectability of lupin by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), ELISAs, LC-MS/MS, and real-time PCR. Seeds were roasted by fluidized bed roasting, and samples were drawn at seed surface temperatures ranging from 98 °C to 242 °C. With increasing roasting temperature, the extractability of proteins and DNA decreased. In addition, roasting resulted in lower detectability of lupin proteins by ELISAs and LC-MS/MS and lower detectability of DNA by real-time PCR. Our results suggest reduced allergenicity of roasted lupin seeds used for the production of "lupin coffee"; however, this has to be confirmed in in vivo studies.

Electrical Fields in the Processing of Protein-Based Foods

Electric field-based technologies offer interesting perspectives which include controlled heat dissipation (via the ohmic heating effect) and the influence of electrical variables (e.g., electroporation). These factors collectively provide an opportunity to modify the functional and technological properties of numerous food proteins, including ones from emergent plant- and microbial-based sources. Currently, numerous scientific studies are underway, contributing to the emerging body of knowledge about the effects on protein properties. In this review, "Electric Field Processing" acknowledges the broader range of technologies that fall under the umbrella of using the direct passage of electrical current in food material, giving particular focus to the ones that are industrially implemented. The structural and biological effects of electric field processing (thermal and non-thermal) on protein fractions from various sources will be addressed. For a more comprehensive contextualization of the significance of these effects, both conventional and alternative protein sources, along with their respective ingredients, will be introduced initially.

Lupin protein-stabilized oil droplets contribute to structuring whey protein emulsion-filled gels

This work aimed to understand the role of lupin protein or mixed lupin-whey protein stabilized oil droplets on the texture and microstructure of a heat-induced whey protein gel. Protein-stabilized emulsions were compared to surfactant-stabilized emulsions to investigate the potential of their interfacial interactions to impart unique structures in the filled gels. The structure development was followed in situ using rheology and the final heat-induced gels were characterized by small and large amplitude oscillatory rheology and confocal microscopy. The development of the gel modulus as well as the final gel properties were linked to the type of interactions between the whey protein matrix and the protein adsorbed at the oil interface. The final gels were selectively dissolved in various buffers, and the results showed that replacing interfacial whey protein with lupin protein resulted in a reduced amount of disulfide bridges, explaining the softer gel in the lupin containing gels compared to those with whey protein. Non-covalent interactions were the main forces involved in the formation of actively filled droplets in the gel network. This work demonstrated that by modulating the interfacial composition of the oil droplets, differing gel structures could be achieved due to differences in the protein-protein interactions between the continuous and the interfacial phase. There is therefore potential for the development of innovative products using lupin-whey protein mixtures, by careful control of the processing steps and the matrix composition.

Compositional Attributes of Blue Lupin (Lupinus angustifolius) Seeds for Selection of High-Protein Cultivars

Lupin is a promising protein source with a high protein concentration. Breeding efforts have resulted in the development of varieties low in quinolizidine alkaloids. The objective of this work was to evaluate 22 different blue lupin genotypes for a high protein concentration and low content of antinutritional alkaloids. These genotypes were grown under uniform controlled environmental and soil conditions, and the harvested seeds were evaluated for their composition. The low phosphorus content confirmed that the phytic acid presence was low in lupin, especially compared to other legumes. Furthermore, some of the varieties had less than 200 ppm alkaloids. Lupin proteins were rich in leucine and lysine, with the lowest amino acid concentration being methionine. There were significant differences in the protein concentration and recovery. This work demonstrated that an approach for selection of genotypes should be based on not only agronomic yields but also nutritional phenotypes, driving better decision making on future varietal selection.

Characterization of texturized meat analogues containing native lupin flour and lupin protein concentrate/isolate

Lupin is a nutritious, yet undervalued grain used as a fodder and food crop. In the present study, native lupin flour (LF), lupin protein concentrate (LPC), and lupin protein isolate (LPI) were combined (70% LPI:LPC blend ratios [30:70, 50:50, and 70:30] and 30% LF constant fraction), extruded at high moisture (45-55%), and shaped with a long cooling die (800 mm) to obtain texturized meat analogues (TMAs) with fibrous structures. The characteristics of TMAs (e.g., hardness, water hydration capacity) depended heavily on water content, blend ratios (LPI:LPC), and to a lesser extent, the long cooling die temperature. Color changes (i.e., L*, b*) were mostly attributed to variations in blend ratios (LPI:LPC). Microstructure analysis showed that TMAs with higher water content (55%) were more likely to have thinner walls and smaller void thickness. Fluorescence imagery revealed that TMAs with lower LPI content presented more homogeneous structures. These findings show that reasonable amounts (30% d.m.) of native lupin flour can be incorporated into meat analogues by maintaining a sufficiently high protein content (>50% d.m.) to trigger the formation of fibrous structures.

Regulatory Effects of ABA and GA on the Expression of Conglutin Genes and LAFL Network Genes in Yellow Lupine (Lupinus luteus L.) Seeds

The maturation of seeds is a process of particular importance both for the plant itself by assuring the survival of the species and for the human population for nutritional and economic reasons. Controlling this process requires a strict coordination of many factors at different levels of the functioning of genetic and hormonal changes as well as cellular organization. One of the most important examples is the transcriptional activity of the LAFL gene regulatory network, which includes LEAFY COTYLEDON1 (LEC1) and LEC1-LIKE (L1L) and ABSCISIC ACID INSENSITIVE3 (ABI3), FUSCA3 (FUS3), and LEC2 (LEAFY COTYLEDON2), as well as hormonal homeostasis-of abscisic acid (ABA) and gibberellins (GA) in particular. From the nutritional point of view, the key to seed development is the ability of seeds to accumulate large amounts of proteins with different structures and properties. The world's food deficit is mainly related to shortages of protein, and taking into consideration the environmental changes occurring on Earth, it is becoming necessary to search for a way to obtain large amounts of plant-derived protein while maintaining the diversity of its origin. Yellow lupin, whose storage proteins are conglutins, is one of the plant species native to Europe that accumulates large amounts of this nutrient in its seeds. In this article we have shown the key changes occurring in the developing seeds of the yellow-lupin cultivar Taper by means of modern molecular biology techniques, including RNA-seq, chromatographic techniques and quantitative PCR analysis. We identified regulatory genes fundamental to the seed-filling process, as well as genes encoding conglutins. We also investigated how exogenous application of ABA and GA3 affects the expression of LlLEC2, LlABI3, LlFUS3, and genes encoding β- and δ-conglutins and whether it results in the amount of accumulated seed storage proteins. The research shows that for each species, even related plants, very specific changes can be identified. Thus the analysis and possibility of using such an approach to improve and stabilize yields requires even more detailed and extended research.

A not-glycosylated isoform of γ-conglutin, a hexameric glycoprotein of Lupinus albus seed, participates in the oligomerization equilibrium

γ-conglutin (γ-C) is a hexameric glycoprotein accumulated in lupin seeds and has long been considered as a storage protein. Recently, it has been investigated for its possible postprandial glycaemic regulating action in human nutrition and for its physiological role in plant defence. The quaternary structure of γ-C results from the assembly of six monomers in reversible pH-dependent association/dissociation equilibrium. Our working hypothesis was that the γ-C hexamer is made up of glycosylated subunits in association with not-glycosylated isoforms, that seem to have 'escaped' the correct glycosylation process in the Golgi. Here we describe the isolation of not-glycosylated γ-C monomers in native condition by two in tandem lectin-based affinity chromatography and the characterization of their oligomerization capacity. We report, for the first time, the observation that a plant multimeric protein may be formed by identical polypeptide chains that have undergone different post-translational modifications. All obtained considered, the results strongly suggest that the not-glycosylated isoform can also take part in the oligomerization equilibrium of the protein.

Conventional solid-state fermentation impacts the white lupin proteome reducing the abundance of allergenic peptides

The demand for high-quality and sustainable protein sources is on the rise. Lupin is an emerging plant-based source of protein with health-enhancing properties; however, the allergenic potential of lupins limits their widespread adoption in food products. A combination of discovery and targeted quantitative proteome measurements was used to investigate the impact of solid-state fermentation induced by Rhizopus oligosporus on the proteome composition and allergenic protein abundances of white lupin seed. In total, 1,241 proteins were uniquely identified in the fermented sample. Moreover, the effectiveness of the solid-state fermentation in reducing the abundance of the tryptic peptides derived from white lupin allergens was demonstrated. Comparably, a greater decrease was noted for the major white lupin allergen based on β-conglutin peptide abundances. Hence, conventional solid-state fermentation processing can be beneficial for reducing the potential allergenicity of lupin-based foods. This finding will open new avenues for unlocking the potential of this under-utilised legume.

Isoelectric point isolation and characterization of proteins from lupine cultivars as influenced by chemical and thermal treatments

Pulses provide a significant nutritional potential for the large proportion of the population in developing countries. Lupine is among the underutilized legume crops for human food in Ethiopia and globally concomitant to its contents of bitter alkaloids. This research was initiated to investigate the effects of soaking lupine seeds of bitter and sweet varieties in water and 2% sodium carbonate (Na₂CO₃) solutions as grain softener on the protein extraction efficiency and its sensory acceptability. It was hypothesized that the soaking treatment results in the removal of characteristic bitterness when coupled with thermal treatment (roasting). The result showed that soaking in Na₂CO₃ significantly increased the protein extraction efficiency (both protein yield and quality (purity)) in the two lupine cultivars. The roasting treatment did not help much. The bitter variety of lupine soaked in Na₂CO₃ with no roasting treatment gave the highest protein yield (39.45%), while the sweet variety soaked in water followed by roasting exhibited the least protein yield (23.25%). The purity of the protein isolates from the lupine samples soaked in 2% Na₂CO₃ followed by roasting was the highest (92.29%). The non-soaked samples of the sweet variety after roasting resulted in the lowest purity (75.05%). The water holding, and oil absorption capacity, as well as the emulsification activity and foaming capacity of the protein isolates were significantly varied for the lupine varieties, and by the soaking and roasting treatments. Higher (314.38%) WHC was recorded for the protein isolates from sweet variety soaked in Na₂CO₃, where the bitter variety, when soaked in 2% Na₂CO₃ without roasting gave protein isolates of higher emulsion and foaming capacities. The research revealed also that soaking of lupine seeds in grain softeners shows a great potential as a pretreatment for enhanced protein extraction and functional desirability (in terms of emulsion and foaming capacities) as well as sensory acceptability and can be recommended for scaling up at industrial level.

Structural and Thermal Characterization of Protein Isolates from Australian Lupin Varieties as Affected by Processing Conditions

Proteins from the full and defatted flours of L. angustifolius cv Jurien and L. albus cv Murringo were prepared using alkaline extraction and iso-electric precipitation. Isolates were either freeze dried or spray dried or pasteurized at 75 ± 3 °C/5 min before freeze-drying. Various structural properties were investigated to elucidate the varietal and processing-induced effect on molecular and secondary structure. Irrespective of processing, isolated proteins had a similar molecular size, with α-conglutin (412 kDa) and β-conglutin (210 kDa) being principal fractions for the albus and angustifolius variety, respectively. Smaller peptide fragments were observed for the pasteurized and spray dried samples, indicating some degree of processing-induced changes. Furthermore, secondary structure characterization by Fourier-transform-infrared and circular dichroism spectroscopy showed β-sheet and α-helical structure being the dominant structure, respectively. Thermal characterization showed two denaturation peaks corresponding to β-conglutin (T_d = 85-89 °C) and α-conglutin (T_d = 102-105 °C) fractions. However, the enthalpy values for α-conglutin denaturation were significantly higher for albus species, which corroborates well with higher amounts of heat stable α-conglutin present. Amino acid profile was similar for all samples with limiting sulphur amino acid. In summary, commercial processing conditions did not have a profound effect on the various structural properties of lupin protein isolates, and properties were mainly determined by varietal differences.

Pulse Globulins 11S and 7S: Origins, Purification Methods, and Techno-functional Properties

A growing interest in pulse proteins in recent years results from their crucial role in the transition toward sustainable food systems. Consequently, current research is mainly focused on the production of protein ingredients and the evaluation of their nutritional and techno-functional properties for the development of animal product analogues. However, the individual impacts of the major proteins 11S legumin and 7S vicilin on pulse techno-functionalities remains unclear. Thus, this review aims to represent current knowledge on pulse 11S and 7S globulin origins, extraction, separation, and purification methods as well as their techno-functionalities. This paper also discusses the principal challenges related to pulse vicilin and legumin purification methods, such as efficiency and environmental concerns, as well as 11S/7S ratio variability. This review highlights the fact that 11S and 7S fractions serve different purposes in pulse functionality and that more efficient and eco-friendly purification techniques are required to properly assess their respective functional attributes. Such research would allow the determination of optimal 11S/7S ratios for the integration of pulse protein ingredients in various food formulations. Hence, food industries would be able to select species/varieties, agronomical methods, and processing methods to produce ingredients with suitable 11S/7S ratios, catering to consumers' ethical, environmental, and nutritional concerns.

High prevalence of lupin allergy among patients with peanut allergy: Identification of γ-conglutin as major allergen

BACKGROUND

Lupin is a protein-rich legume with a growing presence in the food market worldwide. With increased consumption, lupin allergy (LA) reports are also rising. Uncertainties exist on the cross-reactivity between peanut and lupin, the allergenic potential of different lupin species, and sensitization patterns among different populations.

OBJECTIVE

To evaluate the molecular basis of LA and to determine lupin allergens from 3 different species that may be involved in peanut allergy (PA) cross-reactivity.

METHODS

A total of 43 subjects with PA, those with LA, or controls without food allergy were evaluated with skin prick tests (SPTs) and specific IgEs (sIgEs). Lupin-sensitized subjects were offered a lupin oral food challenge (OFC). Immunoblots and enzyme-linked immunosorbent assays were performed on sera from lupin-sensitized subjects.

RESULTS

In this study, 44% of the PA subjects were confirmed to have LA by OFC. Anaphylaxis was the most frequent manifestation after lupin consumption, with a minimal eliciting dosage of 1 g lupin flour. There was no difference in lupin sIgE or SPT wheal size between lupin-sensitized and confirmed LA subjects or in the severity of symptoms among confirmed LA subjects. Sera from lupin-sensitized subjects uniformly reacted to all 3 different lupin species. Immunoblotting and enzyme-linked immunosorbent assays revealed immunoglobulin E binding to α- and γ-conglutin in all analyzed sera, whereas α- and β-conglutin recognition was variable.

CONCLUSION

Our findings reveal a high prevalence of LA among PA subjects, emphasizing lupin must be labeled as an allergen in foods. Owing to high variability in lupin-sIgE and lupin-SPT results, LA diagnosis may require OFC. In our population, γ-conglutin is the major allergen of lupin.

Protein Nanofibrils from Fava Bean and Its Major Storage Proteins: Formation and Ability to Generate and Stabilise Foams

Protein nanofibrils (PNFs) have potential for use in food applications as texture inducers. This study investigated the formation of PNFs from protein extracted from whole fava bean and from its two major storage proteins, globulin fractions 11S and 7S. PNFs were formed by heating (85 °C) the proteins under acidic conditions (pH 2) for 24 h. Thioflavin T fluorescence and atomic force microscopy techniques were used to investigate PNF formation. The foaming properties (capacity, stability, and half-life) were explored for non-fibrillated and fibrillated protein from fava bean, 11S, and 7S to investigate the texturing ability of PNFs at concentrations of 1 and 10 mg/mL and pH 7. The results showed that all three heat-incubated proteins (fava bean, 11S, and 7S) formed straight semi-flexible PNFs. Some differences in the capacity to form PNFs were observed between the two globulin fractions, with the smaller 7S protein being superior to 11S. The fibrillated protein from fava bean, 11S, and 7S generated more voluminous and more stable foams at 10 mg/mL than the corresponding non-fibrillated protein. However, this ability for fibrillated proteins to improve the foam properties seemed to be concentration-dependent, as at 1 mg/mL, the foams were less stable than those made from the non-fibrillated protein.

Combined Gamma Conglutin and Lupanine Treatment Exhibits In Vivo an Enhanced Antidiabetic Effect by Modulating the Liver Gene Expression Profile

Previous studies have individually shown the antidiabetic potential of gamma conglutin (Cγ) and lupanine from lupins. Until now, the influence of combining both compounds and the effective dose of the combination have not been assessed. Moreover, the resulting gene expression profile from this novel combination remains to be explored. Therefore, we aimed to evaluate different dose combinations of Cγ and lupanine by the oral glucose tolerance test (OGTT) to identify the higher antidiabetic effect on a T2D rat model. Later, we administered the selected dose combination during a week. Lastly, we evaluated biochemical parameters and liver gene expression profile using DNA microarrays and bioinformatic analysis. We found that the combination of 28 mg/kg BW Cγ + 20 mg/kg BW lupanine significantly reduced glycemia and lipid levels. Moreover, this treatment positively influenced the expression of Pdk4, G6pc, Foxo1, Foxo3, Ppargc1a, Serpine1, Myc, Slc37a4, Irs2, and Igfbp1 genes. The biological processes associated with these genes are oxidative stress, apoptosis regulation, and glucose and fatty-acid homeostasis. For the first time, we report the beneficial in vivo effect of the combination of two functional lupin compounds. Nevertheless, further studies are needed to investigate the pharmacokinetics and pharmacodynamics of the Cγ + lupanine combined treatment.

Effect of Debittering with Different Solvents and Ultrasound on Carotenoids, Tocopherols, and Phenolics of Lupinus albus Seeds

Lupin seeds represent a rich nutritional source of bioactive compounds, including antioxidant molecules such as carotenoids, tocopherols, and phenolics. However, before consumption, the lupin seeds must be debittered in order to remove their bitter and toxic alkaloids. This study analyzed the impact on the bioactive compounds of Lupinus albus seeds of a recent time- and water-saving debittering method, which employs alternative washing solutions (0.5% or 1% of either NaCl or citric acid), with or without the assistance of ultrasound. The results were compared with those of two control methods using water or a NaCl solution. The sonication, when it was significant, led to a large loss of bioactive compounds, which was most likely due to its extraction capability. The seeds that were debittered without ultrasound presented high concentrations of tocopherols (172.8-241.3 mg/kg DM), carotenoids (10.9-25.1 mg/kg DM), and soluble-free (106.9-361.1 mg/kg DM), soluble-conjugated (93.9-118.9 mg/kg DM), and insoluble-bound (59.2-156.7 mg/kg DM) phenolics. The soluble-free fraction showed the greatest loss after a prolonged treatment. Overall, debittering with citric acid or NaCl preserved the highest concentration of antioxidant compounds by shortening the treatment time, thus preventing extensive leaching.

Multielemental, Nutritional, and Proteomic Characterization of Different Lupinus spp. Genotypes: A Source of Nutrients for Dietary Use

Among grain pulses, lupins have recently gained considerable interest for a number of attractive nutritional attributes relating to their high protein and dietary fiber and negligible starch contents. The seeds of Lupinus albus (cv. Multitalia and Luxor, and the Modica ecotype); L. luteus (cv. Dukat, Mister, and Taper); and L. angustifolius (cv. Sonet) analyzed in this study were deposited within the germplasm collection of the Research Centre for Cereal and Industrial Crops of Acireale and were sowed in East Sicily in 2013/14. The collected seeds were analyzed for their multielemental micro- and macronutrient profiles, resulting in a wide variability between genotypes. Lupin seed flour samples were subjected to a defatting process using supercritical CO₂, with oil yields dependent on the species and genotype. We determined the fatty acid profile and tocopherol content of the lupin oil samples, finding that the total saturated fatty acid quantities of different samples were very close, and the total tocopherol content was about 1500.00 µg/g FW. The proteomic analysis of the defatted lupin seed flours showed substantial equivalence between the cultivars of the same species of Lupinus albus and L. luteus. Moreover, the L. angustifolius proteome map showed the presence of additional spots in comparison to L. albus, corresponding to α-conglutins. Lupin, in addition to being a good source of mineral elements, also contributes vitamin E and, thanks to the very high content of gamma-tocopherols, demonstrates powerful antioxidant activity.

Lupin (Lupinus albus L.) Seeds: Balancing the Good and the Bad and Addressing Future Challenges

Lupinus albus L. (lupine) is a legume whose grain/seed has gained increasing interest. Its recognized nutritional properties, namely a high content of protein, dietary fiber and its low fat content, make lupine a suitable alternative not only for animal protein, but also as a substitute for more processed and less balanced flours from a nutritional point of view, used in the preparation of bread, cakes and cookies, among others. In addition, its nutritional and bioactive compounds have potential benefits for human health in the prevention and treatment of some diseases. However, the existence of some anti-nutritional compounds and contaminants reveal some concern, requiring effective methods for their detection and eventual removal. This review intends to address the potential of lupine (L. albus) in food and human health and to balance the pros and cons. Nutritional and anti-nutritional components of L. albus seeds and possible contaminants of lupine seeds are examined. The potential health benefits of lupine (seeds), including energy metabolism, cardiovascular diseases, hypertension, glucose and insulin metabolism, bower function and anticonvulsant action, are discussed based on scientific evidence (both clinical trials and studies performed with animal models).

An investigation of correlation between structural and functional properties of Nigella sativa protein isolate

The physicochemical characteristics, amino acid composition, and functional properties of Nigella sativa (NS) seedcake protein extracts were evaluated to establish their potential in nutraceuticals and functional foods. The highest yield (20.2%) of protein isolate (NSPI) from NS seedcake was achieved at an alkali concentration of 0.16 M, a buffer to sample ratio of 1/25 (w/v), extraction time, 15 min, and extraction temperature, 25°C. Amino acid analysis showed that the isolated protein is a good source of amino acids with a significant essential to total amino acid (E/TN) ratio. Further, the protein isolate exhibited maximum solubility at pH 11. The results of the physicochemical analysis clearly indicated that the protein isolate had good water and oil holding capacity, emulsification property, foaming capacity, and foaming stability. The secondary structure of NSPI contained α-helix, β-sheet, and β-turns. In addition, NSPI showed excellent antioxidant, anti-diabetic, and protein digestibility activities. From the experimental data, it could be concluded that NSPI could be an excellent source of proteins for the development of foods with promising functional properties. PRACTICAL APPLICATIONS: Nigella sativa seeds are frequently used as a natural food additive and have been a part of naturopathy for centuries due to their anti-inflammatory, antibacterial, anticancer, antidiabetic, immunomodulatory, and cardioprotective properties. Nigella sativa seedcakes obtained as by-products of the oil extraction process are rich in protein content and can be used as a sustainable source of dietary proteins to cater to a wide range of consumers. Being plant-based, they inherently possess several medicinal properties. Analyzing the physicochemical and functional properties of protein isolated from seedcakes allows us to optimize the protein extraction process while providing a better perspective on its potential in the nutraceuticals and food industries. It can be used as an energy supplement in animal feed as a source of protein to replace soybeans and barley. The antioxidant proteins when added to meat-based products have been known to protect the meat from oxidative stress as well as pathogenic organisms, thus, improving its shelf-life. Nigella sativa protein isolates have several applications in the pharmaceutical industry as well.

Effect of Alcalase Modification of Yellow Lupin (Lupinus luteus L.) Protein Isolate on Some Functional Properties and Antioxidant Activity

Protein isolate obtained from sweet yellow lupin (Lupinus luteus L.) and its Alcalase hydrolysates were examined for their functional and antioxidant properties in relation to surface hydrophobicity of proteins and peptides and molecular weight distribution. Enzymatic hydrolysis improved the foaming characteristics of lupin proteins, while the emulsifying properties deteriorated. It means that good foaming properties of preparations are determined by the presence of low-molecular δ conglutin and small subunits of γ conglutins. In turn, larger proteins such as α and β conglutin are responsible for maintaining good emulsifying properties. The measured surface hydrophobicity was consistent with the results of emulsifying properties. It has also been shown that the scope of changes in antioxidant properties due to hydrolysis, measured by DPPH method and as reducing power, is more pronounced than with the use of ABTS and FRAP methods.

The Effect of the Addition of Low-Alkaloid Lupine Flour on the Glycemic Index In Vivo and the Physicochemical Properties and Cooking Quality of Durum Wheat Pasta

The aim of this research was to determine the effect of the addition of lupine flour (LF) on the values of the glycemic index (GI) and glycemic load (GL), physicochemical properties, and cooking quality of durum semolina pasta. The pasta was enriched with 0–25% of lupine flour (LF0-LF25). Additionally, 7.5 and 20% of oat β-glucans, 5% of vital gluten, and 20% of millet flour were used in a selected sample. The addition of 7.5% β-glucans and 5% vital gluten to the product resulted in only a slight decrease in the GI of the products. A significant decrease in pasta GI was noted after the addition of 20% of lupine flour. The product enriched with 20% of lupine flour, 20% of β-glucans, and 20% of millet flour had the lowest glycemic index and glycemic load (GI = 33.75%, GL = 7.2%, respectively). At the same time, the lupine-flour-enriched products were characterized by an increased concentration of protein, fat, ash, and dietary fiber. The addition of lupine flour at the level of up to 20% yielded functional products characterized by good cooking quality.

Lupinus albus γ-Conglutin: New Findings about Its Action at the Intestinal Barrier and a Critical Analysis of the State of the Art on Its Postprandial Glycaemic Regulating Activity

γ-Conglutin (γ-C) is the glycoprotein from the edible seed L. albus, studied for long time for its postprandial glycaemic regulating action. It still lacks clear information on what could happen at the meeting point between the protein and the organism: the intestinal barrier. We compared an in vitro system involving Caco-2 and IPEC-J2 cells with an ex vivo system using pig ileum and jejunum segments to study γ-C transport from the apical to the basolateral compartment, and its effects on the D-glucose uptake and glucose transporters protein expression. Finally, we studied its potential in modulating glucose metabolism by assessing the possible inhibition of α-amylase and α-glucosidase. RP-HPLC analyses showed that γ-C may be transported to the basolateral side in the in vitro system but not in the pig intestines. γ-C was also able to promote a decrease in glucose uptake in both cells and jejunum independently from the expression of the SGLT1 and GLUT2 transporters.

Lupin (Lupinus spp.)-Fortified Bread: A Sustainable, Nutritionally, Functionally, and Technologically Valuable Solution for Bakery

The purpose of this paper is to evaluate the nutritional, phytochemical, rheological, technological, and sensory properties of wheat flour dough and bread under a replacement of lupin flour at level 10, 20, and 30%. In this sense, the proximate composition, fatty acids profile, the content in total polyphenols content (TPC), antioxidant activity (AA), and flavonoids content (TFC) of lupin; wheat and flour composites; and the bread obtained from them were determined. The rheological properties of the dough using the Mixolab system were also evaluated. The results showed an improvement in the nutritional properties of bread with addition of lupin in the composite flour, especially in terms of proteins, lipids, and mineral substances and a significant increases of functional attributes, such as TPC, TFC, and AA, which recorded the highest values in the bread with 30% lupin flour (76.50 mg GAE/100 g, 8.54 mg QE/100 g, 54.98%). The decrease of lupin bread volume compared to wheat bread ranged between 0.69-7.37%, porosity between 6.92-35.26%, elasticity between 63-70%, and H/D between 3.17-19.05%. The rheological profile of the dough obtained with lupin flours indicates a moderate stability and proper kneading behavior. The sensory analysis was also performed in order to identify the consumer's acceptability regarding this type of bread. According to a 5-point hedonic scale, the most highly appreciated was the bread with 10% lupin flour, which obtained mean scores of 4.73 for general acceptability as compared with control bread (4.43).

Ensuring Global Food Security by Improving Protein Content in Major Grain Legumes Using Breeding and 'Omics' Tools

Grain legumes are a rich source of dietary protein for millions of people globally and thus a key driver for securing global food security. Legume plant-based 'dietary protein' biofortification is an economic strategy for alleviating the menace of rising malnutrition-related problems and hidden hunger. Malnutrition from protein deficiency is predominant in human populations with an insufficient daily intake of animal protein/dietary protein due to economic limitations, especially in developing countries. Therefore, enhancing grain legume protein content will help eradicate protein-related malnutrition problems in low-income and underprivileged countries. Here, we review the exploitable genetic variability for grain protein content in various major grain legumes for improving the protein content of high-yielding, low-protein genotypes. We highlight classical genetics-based inheritance of protein content in various legumes and discuss advances in molecular marker technology that have enabled us to underpin various quantitative trait loci controlling seed protein content (SPC) in biparental-based mapping populations and genome-wide association studies. We also review the progress of functional genomics in deciphering the underlying candidate gene(s) controlling SPC in various grain legumes and the role of proteomics and metabolomics in shedding light on the accumulation of various novel proteins and metabolites in high-protein legume genotypes. Lastly, we detail the scope of genomic selection, high-throughput phenotyping, emerging genome editing tools, and speed breeding protocols for enhancing SPC in grain legumes to achieve legume-based dietary protein security and thus reduce the global hunger risk.

Combined Effect of Extraction and Purification Conditions on Yield, Composition and Functional and Structural Properties of Lupin Proteins

Lupin meal presents great potential as an alternative plant-based source of proteins for human nutrition. In the present work, different conditions of extraction and purification were evaluated for production of lupin protein isolates. The results showed that the protein extraction yield was comparable at acidic and conventionally used alkaline extraction pH (37% vs. 40–45%, respectively). Proteins extracted were principally composed of globulins. The ionic strength negatively impacted the protein extractability at pH 2, whereas no significant differences were observed between extractions at 20 to 50 °C. The selected extraction conditions (pH 2 and 7) combined with purification by isoelectric precipitation or ultrafiltration process generated the isolate-grade products. Interestingly, further characterization revealed a partial denaturation of proteins extracted at pH 2 resulting in loss of protein solubility at pH 6 and 7 (10–50%), modifications in secondary structure, lower thermal stability, and formation of protein aggregates. However, foaming and emulsifying properties were generally similar for almost all lupin isolates. Further investigation might be of interest with regard to the extraction behaviours and structural and functional properties of specific lupin protein fractions.

Evaluation of the Major Seed Storage Proteins, the Conglutins, Across Genetically Diverse Narrow-Leafed Lupin Varieties

Lupin seeds have an excellent nutritional profile, including a high proportion of protein and dietary fiber. These qualities make lupin seeds an ideal candidate to help meet the growing global demand for complementary sources of protein. Of consequence to this application, there are nutritional and antinutritional properties assigned to the major lupin seed storage proteins—referred to as α-, β-, δ- and γ-conglutins The variation in the abundance of these protein families can impact the nutritional and bioactive properties of different lupin varieties. Hence, exploring the conglutin protein profiles across a diverse range of lupin varieties will yield knowledge that can facilitate the selection of superior genotypes for food applications or lupin crop improvement. To support this knowledge generation, discovery proteomics was applied for the identification of the 16 known conglutin subfamilies from 46 domestic and wild narrow-leafed lupin (NLL) genotypes. Consequently, the diversity of abundance of these proteins was evaluated using liquid chromatography–multiple reaction monitoring-mass spectrometry (LC–MRM-MS). This comparative study revealed a larger variability for the β- and δ-conglutin content across the lines under study. The absence/lower abundance of the β2- to β6-conglutin subfamilies in a subset of the domesticated cultivars led to substantially lower overall levels of the allergenic β-conglutin content in these NLLs, for which the elevation of the other conglutin families were observed. The diversity of the conglutin profiles revealed through this study—and the identification of potential hypoallergenic genotypes—will have great significance for lupin allergic consumers, food manufactures as well as grain breeders through the future development of lupin varieties with higher levels of desirable bioactive proteins and lower allergen content.

Influence of temperature on secretion and functionality of lupin seed γ-conglutin

BACKGROUND

Basic 7S globulins, a group of proteins commonly found in legumes, undergo the intriguing phenomenon of release from the seeds into hot water. γ-Conglutin is a representative of this group of proteins found in lupin seeds. The physiological significance and the molecular mechanism of the selective release of γ-conglutin from lupin seeds remain unknown. Therefore, the presented study aimed to determine changes in the functionality of this protein in response to the high temperature occurring during lupin seed incubation.

RESULTS

It was confirmed that the main protein fraction released from the seeds during high-temperature incubation was γ-conglutin. The incubation condition favours the occurrence of this protein in a monomeric form, and the temperature used corresponds to its midpoint unfolding temperature. Subsequent analysis carried out on the γ-conglutin monomer revealed changes in its functionality after heat shock. The thermally treated protein shows a considerable increase in its interaction strength with flavonoids. Moreover, the inhibitory activity against glycoside hydrolases was enhanced when γ-conglutin monomer was exposed to specific temperatures.

CONCLUSION

The results of the present study provide a potential explanation of the physiological relevance of γ-conglutin and shed new light on a possible mechanism of its activation upon specific heat treatment. This knowledge will help characterise homologous proteins, which are commonly found in other legumes and undergo a similar heat-induced secretion phenomenon. © 2021 Society of Chemical Industry.

Mixed dairy and plant-based yogurt alternatives: Improving their physical and sensorial properties through formulation and lactic acid bacteria cocultures

Food transition requires incorporating more plant-based ingredients in our diet, thus leading to the development of new plant-based products, such as yogurt alternatives (YAs). This study aimed at evaluating the impact of lactic acid bacteria (LAB) cocultures and formulation on the physico-chemical and sensory properties of YAs. YAs were made by emulsifying anhydrous milk fat (AMF) or coconut oil in milk and lupin protein suspensions. The starters used, in mono- and cocultures, were the strains Lactococcus lactis NCDO2125, Enteroccocus faecalis CIRM-BIA2412 and Lactiplantibacillus plantarum CIRM-BIA1524. Textural properties and metabolites of YAs were evaluated and their sensory properties compared using a sorting task. Some cocultures led to higher firmness, viscosity, and water holding capacity of YAs, compared to monocultures. AMF and a milk:lupin protein ratio of 67:33 gave firmer and more viscous YAs. YAs were sensorially discriminated on the basis of protein ratio and fat type, but not of starters. The cocultures exhibited more diverse functional outputs, such as texturing, production of flavour compounds, proteolysis, when the strains associated in coculture had distinct capacities. Appropriate associations of LAB and formulation offer interesting solutions to improve the perception of YAs, and ultimately, encourage their consumption.

Surface tension of native and modified plant seed proteins

The present review, dedicated to Prof. Zbigniew Adamczyk on the occasion of his 70th anniversary, covers the literature data on surface tension and surface compression (dilational) rheology of the adsorbed layers of 21 plant seed proteins (10 leguminous and 11 non-leguminous plants). They are typically analyzed as protein concentrates or isolates, the latter usually obtained by isoelectric precipitation or diafiltration. Despite generally lower solubility, as compared to their animal counterparts (lactoglobulins, caseins, albumins, etc.), the plant seed proteins are also capable of lowering surface tension and forming viscoelastic adsorbed layers. Many seed proteins serve mostly as amino acids reservoirs for the future seedling (storage proteins), hence their instantaneous amphiphilicity is not always sufficient to induce strong adsorption at the aqueous-air interface. They can be, however, conveniently unfolded, hydrolyzed and/or chemically/enzymatically modified to expose more hydrophilic or hydrophobic patches. As shown in numerous contributions reviewed below, the resulting shift of the hydrophilic-lipophilic balance can boost their surface activity to the level comparable to that of many animal proteins or low molecular weight surfactants. An important advantage of the plant seed proteins over the animal ones is their much lower environmental cost and abundance in many plants (e.g. ~40% in sunflower or soybean seeds).

Lupinus albus Protein Components Inhibit MMP-2 and MMP-9 Gelatinolytic Activity In Vitro and In Vivo

Matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9) are regarded as important clinical targets due to their nodal-point role in inflammatory and oncological diseases. Here, we aimed at isolating and characterizing am MMP-2 and-9 inhibitor (MMPI) from Lupinus albus and at assessing its efficacy in vitro and in vivo. The protein was isolated using chromatographic and 2-D electrophoretic procedures and sequenced by using MALDI-TOF TOF and MS/MS analysis. In vitro MMP-2 and 9 inhibitions were determined on colon adenocarcinoma (HT29) cells, as well as by measuring the expression levels of genes related to these enzymes. Inhibitory activities were also confirmed in vivo using a model of experimental TNBS-induced colitis in mice, with oral administrations of 15 mg·kg^-1. After chromatographic and electrophoretic isolation, the L. albus MMP-9 inhibitor was found to comprise a large fragment from δ-conglutin and, to a lower extent, small fragments of β-conglutin. In vitro studies showed that the MMPI successfully inhibited MMP-9 activity in a dose-dependent manner in colon cancer cells, with an IC50 of 10 µg·mL^-1 without impairing gene expression nor cell growth. In vivo studies showed that the MMPI maintained its bioactivities when administered orally and significantly reduced colitis symptoms, along with a very significant inhibition of MMP-2 and -9 activities. Overall, results reveal a novel type of MMPI in lupine that is edible, proteinaceous in nature and soluble in water, and effective in vivo, suggesting a high potential application as a nutraceutical or a functional food in pathologies related to abnormally high MMP-9 activity in the digestive system.

Effect of Lupinus rotundiflorus gamma conglutin treatment on JNK1 gene expression and protein activation in a rat model of type 2 diabetes

CONTEXT

Gamma conglutin (Cγ) from lupine species represents a potential complementary treatment for type 2 diabetes mellitus (T2DM) because of its hypoglycaemic effect. However, its underlying mechanism of action is not fully known.

OBJECTIVE

To evaluate whether Cγ from Lupinus rotundiflorus M. E. Jones (Fabaceae) modulates c-Jun N-terminal kinase 1 (JNK1) expression and activation in a T2DM rat model.

MATERIALS AND METHODS

Gamma conglutin isolated from L. rotundiflorus seeds was characterized by SDS-PAGE. Fifteen Wistar rats with streptozotocin-induced T2DM (HG) were randomized into three groups (n = 5): vehicle administration (HG-Ctrl), oral treatment with Cγ (120 mg/kg/day) (HG-Lr) for one week, and treatment with metformin (300 mg/kg/day) (HG-Met); a healthy group (Ctrl, n = 5) was included as control. The levels of glucose and biomarkers of renal and hepatic function were measured pre- and post-treatment. Hepatic Jnk1 expression and phosphorylation of JNK1 were evaluated by qRT-PCR and western blot, respectively.

RESULTS

Oral treatment with either Cγ or metformin reduced serum glucose level to 86.30 and 74.80 mg/dL, respectively (p ˂ 0.05), from the basal levels. Jnk1 expression was 0.65- and 0.54-fold lower (p ˂ 0.05) in the HG-Lr and HG-Met groups, respectively, than in HG-Ctrl. Treatment with Cγ decreased JNK1 phosphorylation. However, Cγ did not change the levels of kidney and liver biomarkers.

DISCUSSION AND CONCLUSIONS

Treatment with Cγ from L. rotundiflorus inhibited Jnk1 expression, in vivo, suggesting JNK1 as a potential therapeutic target in diabetes and revealing one mechanism underlying the hypoglycaemic effect of lupine Cγ. Nevertheless, further studies are required.

Extraction, purification by cation exchange supermacroporous cryogel and physico-chemical characterization of γ-conglutin from lupin seeds (Lupinus albus L.)

This study focused on the extraction, purification, and physicochemical characterization of γ-conglutin, a protein present in lupin seeds with properties of reducing blood glucose levels. Total protein was extracted with an alkaline-saline solvent, followed by isoelectric precipitation. Chromatographic purification of the precipitated fraction was performed using a cation exchange supermacroporous cryogel column. Electrophoresis of the eluted fraction from chromatography presented a single band of ∼48 kDa under non-reducing conditions (two bands of ∼30 and ∼17 kDa, under reducing conditions) confirming the success of the purification protocol. Liquid chromatography-tandem mass spectrometry analysis confirmed the identity of the protein as γ-conglutin. The purified γ-conglutin had an isoelectric point of 7.51, β-sheets prevailing as a secondary structure, and denaturation temperature close to 68°C. The outcome of this work showed that γ-conglutin was obtained with a high degree of purity. The proposed purification protocol is simple and can be easily scaled up.

Evaluation of protein extraction methods for in-depth proteome analysis of narrow-leafed lupin (Lupinus angustifolius) seeds

Lupin is slated as a potential contributor towards future food security. Lupin possesses several nutritional and nutraceutical attributes, many linked to seed proteins. For in-depth characterisation of the lupin proteome, liquid chromatography-tandem mass spectrometry was used to evaluate four protein extraction procedures. The proteomes of three narrow-leafed lupin were qualitatively evaluated using protein/peptide identifications and further quantitatively assessed by data-independent proteome measurement. Each extraction buffer led to unique protein identifications; altogether yielding 2,760 protein identifications from lupin varieties. The analysis of protein abundance data highlighted distinct differences between Tris-HCl and urea extracted proteomes, while also revealing variation amongst the cultivar proteomes with the wild accession (P27255) distinctly different from the domesticated cultivars (Tanjil, Unicrop). The extraction buffer used influenced the proteome coverage, downstream functional annotation results and consequently the biological interpretation demonstrating the need to optimise and understand the impact of protein extraction conditions.

An Up-Scalable and Cost-Effective Methodology for Isolating a Polypeptide Matrix Metalloproteinase-9 Inhibitor from Lupinus albus Seeds

One of the most challenging problems with food-borne bioactive compounds is that there are commonly no cost-effective, generally recognized as safe (GRAS) methods for obtaining gram quantities of their purified forms. Here we aimed at developing a method to isolate deflamin, an oligomeric protein from lupin seeds with anti-inflammatory and anticancer activity through matrix metalloprotease (MMP)-9 inhibition. Our goal was to develop a GRAS method that could be easily up-scalable whilst maintaining deflamin’s activity. A sequential precipitation methodology was developed, using an aqueous extraction, followed by heat denaturation, acid precipitation and solubilization in ethanol. A final precipitation with 90% ethanol yielded a purified protein which was sequenced through mass spectrometry and tested for its MMP inhibitory activity using the Dye-quenched (DQ) gelatin assay and the standard wound healing assay in HT29 cells. The developed method yielded a purified oligomer, which represented 0.1% (w/w) of total dry seed weight and was positively confirmed to be deflamin. It further showed to effectively reduce MMP-9 gelatinolytic activity as well as colon cancer cell migration, hence corroborating the effectiveness of our method. Overall, this is the first reported method for isolating an MMP-9 inhibitor from legume seeds, which is up-scalable to an industrial level, in a cost-effective manner.

Lupin protein isolate improves insulin sensitivity and steatohepatitis in vivo and modulates the expression of the Fasn, Gys2, and Gsk3b genes

Although studies on lupin protein isolate (LPI) have indicated the presence of a preventive effect on insulin resistance (IR) and lipid disturbances, their influence on established pathological traits has received little attention. Here, we evaluated the in vivo effects of LPI on IR and steatohepatitis as well as its influence on genes involved in lipid and carbohydrate metabolism. We first induced IR and steatohepatitis in rats by maintaining them on a high-fat diet for 5 weeks. Thereafter, we administered LPI to the rats daily for 3 weeks. LPI improved insulin sensitivity (AUC: 6,777 ± 232 vs. 4,971 ± 379, p < .05, pre- vs. post-treatment values) and reduced glucose and triglyceride levels by one-third. In addition, LPI-treated rats exhibited attenuated steatohepatitis. At the molecular level, LPI treatment reduced liver Fasn gene expression substantially but increased Gys2 and Gsk3b levels. We concluded that the hypolipidemic and hypoglycemic activities of LPI may be caused by reduced liver lipogenesis and modulation of insulin sensitization mechanisms.