Lupinus angustifolius L. lactofermentation and protein isolation: effects on phenolic compounds and genistein, antioxidant properties, trypsin inhibitor activity, and protein digestibility

A Comprehensive Review of Antinutrients in Plant-Based Foods and Their Key Ingredients

In recent years, the growing popularity of vegan and vegetarian diets, along with the rising demand for plant-based foods, has led researchers to concentrate on examining the presence and effects of antinutrients. While there are existing literature reviews focusing on antinutritional compounds, particularly on their reduction, this review aims to provide a comprehensive description of antinutrients for producers, food scientists, professionals, legislators and consumers, emphasising the complexity of the subject and the necessity for diverse approaches while identifying aspects that still require further research. Antinutrients, including protease inhibitors, amylase inhibitors, phytic acid, lectins, saponins, tannins, cyanogenic glycosides, oxalic acid, polyphenols, goitrogens and pyrimidine glycosides, are described, encompassing various aspects such as their structural characteristics, analytical detection methods, distribution, physiological impacts and strategies for mitigation or elimination. Specifically, our review concentrates on assessing the presence of antinutrients in plant-based food products and the primary ingredients, categorised into five distinct groups, cereals, pseudocereals, pulses, seeds and nuts, which are commonly used in their production. Among these categories, legumes are identified as the richest source of anti-nutritional compounds, followed by cereal grains. However, certain pseudocereals, seeds and nuts also demonstrate high levels of specific antinutrients. While antinutrients are generally regarded as harmful to nutrient absorption, recent studies have revealed some potential health benefits associated with them. Therefore, further in vivo research is essential to elucidate the behaviour of antinutritional compounds within the human body. Additionally, there is a significant lack of formal regulations and guidelines regarding antinutrients, and food products currently do not feature labelling related to these compounds.

Influence of different lactic acid bacteria strains and milling process on the solid-state fermented green and red lentils (Lens culinaris L.) properties including gamma-aminobutyric acid formation

The aim of this study was to evaluate the influence of lactic acid bacteria (LAB) strains (Lactiplantibacillus plantarum No.122 and Lacticaseibacillus casei No.210) and milling process on the solid-state fermented (for 24 h, at 30°C) green and red lentils (Lens culinaris L.) properties, chiefly pH, LAB viable counts, color coordinates, free amino acid (FAA) profile, γ-aminobutyric acid (GABA) and biogenic amine (BA) concentrations, fatty acid (FA) and volatile compound (VC) profiles. Results showed that both of the tested LAB strains are suitable for the fermentation of lentils: pH of fermented lentils was <4.5 and LAB viable counts >8.0 log10 colony-forming units (CFU)/g. A very strong negative correlation was found (r = -0.973, p ≤ 0.0001) between LAB counts and pH of the samples. Also, fermentation and milling process were significant factors toward color coordinates of the lentils. In most of the cases, solid-state fermentation (SSF) increased essential FAA content in lentils; however, some of the non-essential FAA content was reduced. SSF significantly increased GABA concentration in lentils and milling process was a significant factor on GABA content of the samples (p ≤ 0.05). The main BA in lentils was spermidine, and SSF decreased their total BA content (34.8% on average in red lentils and 39.9% on average in green lentils). The main FA in lentils were linoleic and oleic. The main VC in lentils were hexanal, 1-hexanol, hexanoic acid, D-limonene and (E)-2-nonen-1-ol. Furthermore, most of the VC showed significant correlations with pH of lentil samples, LAB counts and FA content. Finally, the LAB strain used for fermentation and the milling process of lentils are significant factors for most of the analyzed parameters in lentil. Moreover, despite the higher GABA concentration found in green non-milled SSF lentils, application of combined milling and SSF is recommended because they showed the lowest BA content in addition to higher essential FAA and GABA concentrations.

Effect of Fractionation and Processing Conditions on the Digestibility of Plant Proteins as Food Ingredients

Plant protein concentrates and isolates are used to produce alternatives to meat, dairy and eggs. Fractionation of ingredients and subsequent processing into food products modify the techno-functional and nutritional properties of proteins. The differences in composition and structure of plant proteins, in addition to the wide range of processing steps and conditions, can have ambivalent effects on protein digestibility. The objective of this review is to assess the current knowledge on the effect of processing of plant protein-rich ingredients on their digestibility. We obtained data on various fractionation conditions and processing after fractionation, including enzymatic hydrolysis, alkaline treatment, heating, high pressure, fermentation, complexation, extrusion, gelation, as well as oxidation and interactions with starch or fibre. We provide an overview of the effect of some processing steps for protein-rich ingredients from different crops, such as soybean, yellow pea, and lentil, among others. Some studies explored the effect of processing on the presence of antinutritional factors. A certain degree, and type, of processing can improve protein digestibility, while more extensive processing can be detrimental. We argue that processing, protein bioavailability and the digestibility of plant-based foods must be addressed in combination to truly improve the sustainability of the current food system.

Nutritional and Rheological Features of Lentil Protein Isolate for Yoghurt-Like Application

The substitution of animal protein with proteins of plant origin is a viable way to decrease the negative impact caused by animal husbandry on the environment. Pulse consumption has been widely promoted as a nutritious contribution to protein supplementation. In this study, an emulsion of lentil (Lens culinaris) protein isolate is fermented with lactic acid bacteria (LAB) to manufacture a yoghurt alternative and the techno-functional properties compared to a dairy- and a soy-based product with similar protein contents. The yoghurt-like products are subjected to large and small deformation analysis, quantification of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP), water holding capacity tests, protein profile analysis and the gel structure is visualised by confocal laser scanning microscopy (CLSM). The lentil yoghurt alternative shows good water holding capacity, high firmness and consistency values in large deformation analysis, with cohesiveness and viscosity not significantly different from that of dairy yoghurt. The high gel strength and rigidity of the lentil yoghurt gels measured by small deformation analysis is well-reflected in the dense protein matrix in the CLSM graphs. FODMAP content of the lentil yoghurt is very low, making it suitable for consumption by irritable bowel syndrome (IBS) patients. Our results show that lentil protein isolate is an excellent base material for producing a plant-based yoghurt alternative.

Nutritional properties and health aspects of pulses and their use in plant-based yogurt alternatives

Plant-based yogurt alternatives are increasing in market value, while dairy yogurt sales are stagnating or even declining. The plant-based yogurt alternatives market is currently dominated by products based on coconut or soy. Coconut-based products especially are often low in protein and high in saturated fat, while soy products raise consumer concerns regarding genetically modified soybeans, and soy allergies are common. Pulses are ideally suited as a base for plant-based yogurt alternatives due to their high protein content and beneficial amino acid composition. This review provides an overview of pulse nutrients, pro-nutritional and anti-nutritional compounds, how their composition can be altered by fermentation, and the chemistry behind pulse protein coagulation by acid or salt denaturation. An extensive market review on plant-based yogurt alternatives provides an overview of the current worldwide market situation. It shows that pulses are ideal base ingredients for yogurt alternatives due to their high protein content, amino acid composition, and gelling behavior when fermented with lactic acid bacteria. Additionally, fermentation can be used to reduce anti-nutrients such as α-galactosides and vicine or trypsin inhibitors, further increasing the nutritional value of pulse-based yogurt alternatives.

Solid-state fermented plant protein sources in the diets of broiler chickens: A review

Protein sources are the second most important component in poultry diets. Due to the fluctuation in price of soybean meal (SBM) and persistent increase in feed prices, nutritionists have been exploring alternative protein sources. Replacement of SBM with alternative protein sources in poultry diets could reduce human-livestock competition for soybean and support the production of more animal protein. However, the use of alternative protein sources is limited to low inclusion due to the presence of anti-nutritional factors (ANF) such as glucosinolates (rapeseed meal), gossypol (cottonseed meal), non-starch polysaccharides (NSP) in lupin flour, high fibre (palm kernel cake), total phenolic contents and phytic acid (canola meal) known to impair animal performance, nutrient digestibility and feed utilization. As a processing technique, solid-state fermentation (SSF) has been researched for a long time in the food industry. An important objective of SSF is the production of enzymes, organic acids and other metabolites of economic importance. In recent times, SSF has been employed to enhance nutrient bioavailability, inhibit gut pathogenic bacteria and reduce ANF in plant protein sources resulting in improved nutrient digestibility, thereby improving performance and gut health of broiler chickens. Unlike pigs, there is still a dearth of information on feeding solid-state fermented feed ingredients to broiler chickens. This review aims to describe the nutritional value of the solid-state fermented products of rapeseed meal, canola meal, cottonseed meal, palm kernel cake and lupin flour on performance and intestinal health of broiler chickens.