Production of pulse protein ingredients and their application in plant-based milk alternatives

Background: Plant-based milk alternatives are surging in popularity, although many examples have poor nutritional value compared to cow?s milk. At the same time, protein concentrates and isolates from pea and other pulses are increasingly being recognised for their potential as functional and nutritious ingredients. Scope and approach: This review contains an overview of pulse proteins and the dry and wet fractionation methods used to produce high-protein ingredients. The influence of pulse type and processing on the technofunctional properties of ingredients is discussed. Additionally, the application of pulse protein ingredients in milk alternatives is explored, with the goal of providing high protein alternatives to cow?s milk. Key findings and conclusions: Pulse proteins ingredients have received much interest for their functionality and potential to replace animal proteins. A considerable amount of research has been generated encompassing novel protein sources, as well as processing methods, with the aim of producing highly functional ingredients. The functional properties of pulse proteins along with the high protein content of isolates/concentrates provide the opportunity to formulate plant-based milk alternatives with higher nutritional value compared to many others currently on the market. Such products containing pea protein are now available, and various other pulse proteins could also be applied in these products as they become more widely available

Physicochemical and nutritional properties of high protein emulsion-type lupin-based model milk alternatives: effect of protein source and homogenization pressure

Background: Plant-based milk alternatives are becoming more popular. However, many are low in nutrients, particularly protein. More attention is being given to plant protein isolates / concentrates as potential ingredients in high-protein milk alternative formulations. Results: The effect of lupin protein source on the physicochemical, functional, and nutritional characteristics of model milk alternatives was investigated. Milk alternatives were produced with either blue lupin or white lupin protein isolate, formulated to contain similar levels of protein and fat as low-fat cow's milk. Nutritional composition and predicted glycemic properties were measured. The effect of homogenization pressure on the physicochemical properties and storage stability was also assessed, with cow's milk and soy milk alternative analyzed for comparison. Both blue and white lupin milk alternatives were high in protein, low in fermentable oligo-, di- and monosaccharides, and polyols (FODMAPs), and had a low predicted glycemic index. White lupin milk alternatives had smaller particle size as well as greater stability, with less creaming compared to blue lupin milk alternatives, although the former showed slightly higher sediment layers. Increasing homogenization pressure from 180 to 780 bar resulted in smaller particle size, lower separation rate, and greater foamability for both blue and white lupin milk alternatives. White lupin milk alternative homogenized at 780 bar was found to be the most stable product, with a similar separation rate to cow's milk. Conclusions: These results indicate that protein source and processing can influence functional properties significantly along with product stability, and this is an important consideration when formulating high-protein milk alternatives

Rejuvenated brewer's spent grain: the impact of two BSG-derived ingredients on techno-functional and nutritional characteristics of fibre-enriched pasta

Brewer's Spent Grain (BSG), rich in fibre and protein is mostly used for animal feed but has great potential to be used as an ingredient for cereal based products. Originated from BSG, the two ingredients EverVita Fibra (EVF) high in fibre; and EverVita Pro (EVP) high in protein, were used to produce fibre-enriched pasta and compared to semolina, wholemeal flour and a commercial fibre-rich pasta. Analysis of gluten network development and pasting properties revealed the formation of a stronger network by the incorporation of EVP resulting in a compact pasta structure which led to a higher pasta firmness and tensile strength and a decrease in predicted glycaemic index compared to the controls. EVF resulted in an inferior product compared to EVP but was comparable to the semolina control. Hence, EVF and EVP have the potential to increase nutritional value of pasta while maintaining or even improving pasta quality and encouraging the recycling of by-streams for food production

Techno-functional, nutritional and environmental performance of protein isolates from blue lupin and white lupin

Similarly prepared protein isolates from blue lupin (Lupinus angustifolius) and white lupin (L. albus) were assessed in relation to their composition, functional properties, nutritional attributes and environmental impacts. Blue lupin protein isolate (BLPI) and white lupin protein isolate (WLPI) were found to be quite similar in composition, although differences in the electrophoretic protein profiles were apparent. Both lupin protein isolates (LPIs) had good protein solubility (76.9% for BLPI and 69.8% for WLPI at pH 7) and foaming properties. However, a remarkable difference in heat gelation performance was observed between BLPI and WLPI. WLPI had a minimum gelling concentration of 7% protein, whereas BLPI required 23% protein in order to form a gel. WLPI also resulted in stronger gels over a range of concentrations compared to BLPI. Nutritional properties of both LPIs were similar, with no significant differences in in vitro protein digestibility (IVPD), and both had very low trypsin inhibitor activity (TIA) and fermentable oligo-, di- and monosaccharides, and polyols (FODMAP) content. The amino acid profiles of both LPIs were also similar, with sulfur-containing amino acids (SAAs) being the limiting amino acid in each case. Environmental impacts revealed by the life cycle assessment (LCA) were almost identical for BLPI and WLPI, and in most categories the LPIs demonstrated considerably better performance per kg protein when compared to cow’s whole milk powder

Characterisation of pulse protein ingredients produced using different protein sources and processing technology, and potential for application in milk alternatives

In the face of the growing global population along with climate and food security concerns, there is currently much interest in developing plant protein ingredients from sustainable sources. Pulses are a valuable source of protein which could play an increased role in reducing our reliance on animal protein. Pulse protein ingredients can potentially provide the required functional properties (e.g., solubility, emulsifying, gelling, foaming) for a range of food applications. However, further development is necessary in order to increase our understanding and maximise the utility of pulse proteins as demand increases. This thesis addresses how protein source and processing can impact various properties of ingredients, including functional, nutritional and environmental aspects. In addition, the application of pulse proteins in high protein milk alternatives is examined. Furthermore, the impact of enzymatic hydrolysis on physicochemical and functional properties is explored. Protein isolates from blue lupin (Lupinus angustifolius) and white lupin (L. albus) were compared to assess the influence of protein source on various properties. Electrophoresis revealed major differences in molecular weight distribution. Solubility and foaming properties were similar for both isolates, while major differences in thermal gelling behaviour were found, with white lupin protein gelling at a lower concentration (7%) compared to blue lupin (23%). Both isolates were low in FODMAPs (fermentable mono-, di, oligosaccharides and polyols). In addition, the life cycle assessment (LCA) showed generally lower environmental impacts for the lupin isolates compared to milk powder per kg protein. Faba bean protein-rich flour (FPR) produced using dry fractionation was compared to faba bean protein isolate (FPI) produced using wet fractionation. Protein content of dry matter was lower for FPR (64.1%) compared to FPI (90.1%) Overall, superior functionality was found for FPR, including solubility and foaming properties. Wet processing (FPI) was found to be effective for removal of vicine, and trypsin inhibitors and FODMAPs. In the LCA, lower environmental impacts were found for FPR than FPI; however, both FPR and FPI had much lower impacts compared to milk powder. Milk alternatives were produced with blue lupin (BL) or white lupin (WL) protein isolate, with similar protein and fat content to low-fat cow’s milk. Both BL and WL milk alternatives had good colloidal stability and were suitable for low FODMAP diets. Increased homogenisation pressure (780 bar vs 180 bar) resulted in smaller particle size and increased stability for both BL and WL milk alternatives. WL milk alternative homogenised at 780 bar had the lowest separation rate, comparable to low fat cow’s milk, indicating good resistance to creaming. The effects of enzymatic hydrolysis on the physicochemical and functional properties of lentil protein isolate were assessed, in a comparison of three proteases. Hydrolysis with Alcalase or Novozym 11028 resulted in considerably higher solubility from pH 4–6, where the control showed poor solubility. Hydrolysis with Flavourzyme resulted in moderately increased solubility in this pH range, but slightly decreased solubility at neutral pH. Foaming properties were not impacted significantly by hydrolysis. Hydrolysis with Alcalase resulted in larger particle size and higher viscosity compared to the control. Overall, these studies provide useful insight into the properties of pulse protein ingredients which depend on pulse type and ingredient processing, modification with enzymatic hydrolysis, as well as their suitability for high protein milk alternatives

Enzymatic hydrolysis of pulse proteins as a tool to Improve techno-functional properties

Pulse proteins are being increasingly investigated as nutritious and functional ingredients which could provide alternatives to animal proteins; however, pulse protein ingredients do not always meet the functionality requirements necessary for various applications. Consequently, enzymatic hydrolysis can be employed as a means of improving functional properties such as solubility, emulsifying, foaming, and gelling properties. This review aims to examine the current literature regarding modification of these properties with enzymatic hydrolysis. The effects of enzymatic hydrolysis on the functionality of pulse proteins generally varies considerably based on the enzyme, substrate, processing steps such as heat treatment, degree of hydrolysis, and pH. Differences in protease specificity as well as protein structure allow for a wide variety of peptide mixtures to be generated, with varying hydrophobic and electrostatic properties. Typically, the most significant improvements are seen when the original protein ingredient has poor initial functionality. Solubility is usually improved in the mildly acidic range, which may also correspond with improved foaming and emulsifying properties. More work should be carried out on the potential of enzymatic hydrolysis to modify gelation properties of pulse proteins, as the literature is currently lacking. Overall, careful selection of proteases and control of hydrolysis will be necessary to maximize the potential of enzymatic hydrolysis as a tool to improve pulse protein functionality and broaden the range of potential applications