Raw and roasted pistachio nuts (Pistacia vera L.) are 'good' sources of protein based on their digestible indispensable amino acid score as determined in pigs

The pig is an excellent model to determine amino acid digestibility of human foods and to generate data needed to meet human amino acid requirements

The protein value of any food item is determined by the quantity and ileal digestibility of indispensable amino acids in that food. To determine the ileal digestibility of amino acids, an animal model needs to be used, and the pig is the preferred model because values for ileal digestibility obtained in pigs are representative of values obtained in humans. In addition, pigs are omnivorous animals like humans, they are meal eaters, they consume most diets that humans consume, they are easy to work with, and they can be used for repeated determinations of digestibility in many foods. It is, therefore, possible to use pigs to establish a database with digestibility values for human foods and by correcting digestibility values obtained in pigs for the basal endogenous losses of amino acids, it is possible to calculate true ileal digestibility values that are additive in mixed meals. As a consequence, the protein quality of a meal consisting of several food items can be calculated based on digestibility values obtained in pigs. Future work needs to focus on expanding existing databases for amino acid digestibility in foods to include more food items, which will make it possible to estimate the amino acid value of more mixed meals. It is also necessary that the amino acid values in mixed meals be related to requirements for digestible indispensable amino acids in the individuals consuming the meals. The current contribution describes the basic steps in determining amino acid digestibility in human foods using the pig as a model and also outlines future steps needed to further improve amino acid nutrition in humans.

Secondary Bioactive Metabolites from Foods of Plant Origin as Theravention Agents against Neurodegenerative Disorders

Neurodegenerative disorders (NDDs) such as Alzheimer's (AD) and Parkinson's (PD) are on the rise, robbing people of their memories and independence. While risk factors such as age and genetics play an important role, exciting studies suggest that a diet rich in foods from plant origin may offer a line of defense. These kinds of foods, namely fruits and vegetables, are packed with a plethora of powerful bioactive secondary metabolites (SBMs), including terpenoids, polyphenols, glucosinolates, phytosterols and capsaicinoids, which exhibit a wide range of biological activities including antioxidant, antidiabetic, antihypertensive, anti-Alzheimer's, antiproliferative, and antimicrobial properties, associated with preventive effects in the development of chronic diseases mediated by oxidative stress such as type 2 diabetes mellitus, respiratory diseases, cancer, cardiovascular diseases, and NDDs. This review explores the potential of SBMs as theravention agents (metabolites with therapeutic and preventive action) against NDDs. By understanding the science behind plant-based prevention, we may be able to develop new strategies to promote brain health and prevent the rise in NDDs. The proposed review stands out by emphasizing the integration of multiple SBMs in plant-based foods and their potential in preventing NDDs. Previous research has often focused on individual compounds or specific foods, but this review aims to present a comprehensive fingerprint of how a diet rich in various SBMs can synergistically contribute to brain health. The risk factors related to NDD development and the diagnostic process, in addition to some examples of food-related products and medicinal plants that significantly reduce the inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), are highlighted.

Effects of Peanuts and Pistachios on Gut Microbiota and Metabolic Syndrome: A Review

There is growing evidence that the gut microbiota is associated with various aspects of human health, including immune system regulation, vitamin synthesis, short-chain fatty acid production, etc. Peanuts and pistachios are foods rich in protein, unsaturated fatty acids, vitamins, polyphenols, and other dietary components that have been shown to benefit the gut microbiota. Therefore, this review aims to describe the effects of consuming peanuts and pistachios on the gut microbiota and the potential role of these microbiota in human health. This review suggests that the consumption of peanuts or pistachios can demonstrate the potential to exert a beneficial effect on the gut microbiota by promoting the growth of beneficial gut bacteria that produce, for example, short-chain fatty acids that are beneficial for human health. In the case of peanuts, in particular, the possible modulation of the microbiota is associated with an improvement in the risk factors of metabolic syndrome and the inflammatory process triggered by a high-fat diet.

Pistachios as a recovery food following downhill running exercise in recreational team-sport individuals

We aimed to investigate the impact of pistachio nut consumption on muscle soreness and function following exercise-induced muscle damage. Using a randomised cross-over design, male team-sport players (n = 18) performed a 40-minute downhill treadmill run to induce muscle damage, which was conducted after 2-wks of consuming either control (CON, water), a standard dose of daily pistachios (STD, 42.5 g/d) or a higher dose of daily pistachios (HIGH, 85 g/d). Lower limb muscle soreness (visual analogue scale), muscle function (maximal voluntary isokinetic torque and vertical jump), and blood markers of muscle damage/inflammation (creatine kinase, C-reactive protein, myoglobin, superoxide dismutase) were measured pre (baseline) and post (24, 48, and 72 h) exercise. No trial order effects were observed for any outcome measurement across trials. Mean quadriceps soreness (non-dominant leg) during exercise recovery was reduced (p < 0.05) in HIGH vs. CON (mean difference (95%CI): 13(1-25) mm). Change in soreness in the dominant quadriceps was not different between HIGH vs. CON (p = 0.06; mean difference (95%CI): 13(-1 to 26 mm)). No main effects of time or trial were observed for mean soreness of hamstrings, or on isokinetic torque of knee extensors or knee flexors, during recovery. Serum creatine kinase concentration peaked at 24 h post-damage (mean(SEM): 763(158)µg/L) from baseline (300(87)µg/L), but had returned to baseline by 72 h post (398(80)µg/L) exercise in all trials, with no trial or trial × time interaction evident. These data suggest that high dose pistachio nut ingestion may provide some alleviation of muscle soreness, but no effect on muscle function, following modest muscle damage.

Effect of heat treatment on protein quality of rapeseed protein isolate compared with non-heated rapeseed isolate, soy and whey protein isolates, and rice and pea protein concentrates

BACKGROUND

Rapeseed protein isolate is used in the food industry, and heating is often used during rapeseed processing. However, the digestible indispensable amino acid score (DIAAS) for heat-treated rapeseed protein isolate is unknown. The present study aimed to test the hypothesis that heating rapeseed protein isolate improves protein quality resulting in DIAAS that is greater than for pea and rice protein concentrates, and comparable to that of soy and whey protein isolates.

RESULTS

Standardized ileal digestibility (SID) of amino acids (AA), except leucine and methionine, was not different between heat-treated rapeseed protein isolate and soy protein isolate, but SID of most AA was greater (P < 0.001) for heat-treated rapeseed protein isolate than for brown rice protein concentrate, pea protein concentrate, rapeseed protein isolate and soy protein isolate, but not whey protein isolate. Non-heated rapeseed protein isolate had a reduced (P < 0.001) DIAAS for 6-month-old to 3-year-old children compared with soy protein isolate, but this was greater (P < 0.001) than for pea and brown rice protein concentrates. The DIAAS for heat-treated rapeseed protein isolate was greater (P < 0.001) than for non-heated rapeseed protein isolate for all age groups. Heat-treated rapeseed protein isolate and whey protein isolate had a DIAAS > 100 for individuals older than 3 years.

CONCLUSION

Rapeseed protein isolate had a DIAAS comparable to soy protein isolate, but heat-treated rapeseed protein isolate and whey protein isolate had DIAAS ≥ 100, qualifying these proteins as 'excellent'. Rice and pea protein concentrates had DIAAS < 75. © 2023 Society of Chemical Industry.

Plant-Based Dairy Alternatives-A Future Direction to the Milky Way

One significant food group that is part of our daily diet is the dairy group, and both research and industry are actively involved to meet the increasing requirement for plant-based dairy alternatives (PBDAs). The production tendency of PBDAs is growing with a predictable rate of over 18.5% in 2023 from 7.4% at the moment. A multitude of sources can be used for development such as cereals, pseudocereals, legumes, nuts, and seeds to obtain food products such as vegetal milk, cheese, cream, yogurt, butter, and different sweets, such as ice cream, which have nearly similar nutritional profiles to those of animal-origin products. Increased interest in PBDAs is manifested in groups with special dietary needs (e.g., lactose intolerant individuals, pregnant women, newborns, and the elderly) or with pathologies such as metabolic syndromes, dermatological diseases, and arthritis. In spite of the vast range of production perspectives, certain industrial challenges arise during development, such as processing and preservation technologies. This paper aims at providing an overview of the currently available PBDAs based on recent studies selected from the electronic databases PubMed, Web of Science Core Collection, and Scopus. We found 148 publications regarding PBDAs in correlation with their nutritional and technological aspects, together with the implications in terms of health. Therefore, this review focuses on the relationship between plant-based alternatives for dairy products and the human diet, from the raw material to the final products, including the industrial processes and health-related concerns.

Believe It or 'Nut': Why It Is Time to Set the Record Straight on Nut Protein Quality: Pistachio (Pistacia vera L.) Focus

There are growing public health movements to transition towards diets that are plant-based. However, confusion exists with concerns that plant-based proteins (including nuts) may be inferior with respect to protein quality. The present publication evaluates the evolution of protein quality concepts and explains the protein science related to pistachios. Pistachio nuts are a plant-based complete protein providing all nine EAAs in addition to an array of nutrients and phytochemicals. They have a PDCAAS of 73 and 81%, (raw and roasted pistachios, respectively), higher than that of many other tree nuts. From an environmental perspective transitioning towards plant-based diets (including nuts) could have potential to reduce total/green water footprints. Dietary guidelines are evolving yet nuts such as pistachios do not always have a clear place within these. Now appears to be a pertinent time to look at protein quality from the perspective of whole daily diets and dietary patterns, factoring in both health and environmental outcomes. Given updated modes of thinking, nuts such as pistachios have an important role to play in terms of providing ready-to-eat, good-quality, plant-based protein within daily diets.

Oral bioavailability of bioactive compounds; modulating factors, in vitro analysis methods, and enhancing strategies

Foods are complex biosystems made up of a wide variety of compounds. Some of them, such as nutrients and bioactive compounds (bioactives), contribute to supporting body functions and bring important health benefits; others, such as food additives, are involved in processing techniques and contribute to improving sensory attributes and ensuring food safety. Also, there are antinutrients in foods that affect food bioefficiency and contaminants that increase the risk of toxicity. The bioefficiency of food is evaluated with bioavailability which represents the amount of nutrients or bioactives from the consumed food reaching the organs and tissues where they exert their biological activity. Oral bioavailability is the result of some physicochemical and biological processes in which food is involved such as liberation, absorption, distribution, metabolism, and elimination (LADME). In this paper, a general presentation of the factors influencing oral bioavailability of nutrients and bioactives as well as the in vitro techniques for evaluating bioaccessibility and is provided. In this context, a critical analysis of the effects of physiological factors related to the characteristics of the gastrointestinal tract (GIT) on oral bioavailability is discussed, such as pH, chemical composition, volumes of gastrointestinal (GI) fluids, transit time, enzymatic activity, mechanical processes, and so on, and the pharmacokinetics factors including BAC and solubility of bioactives, their transport across the cell membrane, their biodistribution and metabolism. The impact of matrix and food processing on the BAC of bioactives is also explained. The researchers' recent concerns for improving oral bioavailability of nutrients and food bioactives using both traditional techniques, for example, thermal treatments, mechanical processes, soaking, germination and fermentation, as well as food nanotechnologies, such as loading of bioactives in different colloidal delivery systems (CDSs), is also highlighted.

The effect of gamma irradiation, microwaves, and roasting on aflatoxin levels in pistachio kernels

Pistachio is the second largest non-oil export in Iran. The most important problem in pistachio export is its contamination with aflatoxin. Therefore, this study aimed to evaluate the effects of several physical and chemical methods on the qualitative, qualitative and sensory properties of pistachios from Iran as well as the associated residual aflatoxin levels. This study investigated the effects of roasting (temperature 120 °C for 20 and 40 min), gamma radiation (2.5 and 5 KGy), and microwave (1 and 2 min) methods on pistachios and their qualitative characteristics, including moisture, colour, and sensory properties. In addition, aflatoxin B1 and total aflatoxins were artificially added to pistachios to determine the level of aflatoxin remaining after chemical and physical methods. The results showed that the lowest residual level of aflatoxin B1 was related to combined microwave and irradiation methods. Further, the combined methods showed the lowest total aflatoxins residue so the lowest total aflatoxins residue after chemical contamination of 8 μg/kg aflatoxin was related to the combined methods of 5 KGy irradiations with 2 min of the microwave. In addition, the microwaved and irradiated samples did not differ significantly from the control samples in terms of sensory characteristics (P<0.05). It can be concluded that these methods can be successfully applied without adversely affecting the characteristics of pistachios. Considering the position of pistachios in domestic and global markets, these processes can be used to reduce aflatoxins, improve the quality of pistachios, and increase export.

The current status of old traditional medicine introduced from Persia to China

Traditional Chinese medicine (TCM) includes over ten thousand herbal medicines, some of which were introduced from outside countries and territories. The Silk Road enabled the exchange of merchandise such as teas, silks, carpets, and medicines between the East and West of the Eurasia continent. During this time, the ‘Compendium of Materia Medica’ (CMM) was composed by a traditional medicine practitioner, Shizhen Li (1,518–1,593) of the Ming Dynasty. This epoch-making masterpiece collected knowledge of traditional medical materials and treatments in China from the 16th century and before in utmost detail, including the origin where a material was obtained. Of 1892 medical materials from the CMM, 46 came from Persia (now Iran). In this study, the basic information of these 46 materials, including the time of introduction, the medicinal value in TCM theory, together with the current status of these medicines in China and Iran, are summarized. It is found that 20 herbs and four stones out of the 46 materials are registered as medicinal materials in the latest China Pharmacopoeia. Now most of these herbs and stones are distributed in China or replacements are available but saffron, ferula, myrrh, and olibanum are still highly dependent on imports. This study may contribute to the further development, exchange, and internationalization of traditional medicine of various backgrounds in the world, given the barriers of transportation and language are largely eased in nowadays.

Legume Seed Protein Digestibility as Influenced by Traditional and Emerging Physical Processing Technologies

The increased consumption of legume seeds as a strategy for enhancing food security, reducing malnutrition, and improving health outcomes on a global scale remains an ongoing subject of profound research interest. Legume seed proteins are rich in their dietary protein contents. However, coexisting with these proteins in the seed matrix are other components that inhibit protein digestibility. Thus, improving access to legume proteins often depends on the neutralisation of these inhibitors, which are collectively described as antinutrients or antinutritional factors. The determination of protein quality, which typically involves evaluating protein digestibility and essential amino acid content, is assessed using various methods, such as in vitro simulated gastrointestinal digestibility, protein digestibility-corrected amino acid score (IV-PDCAAS), and digestible indispensable amino acid score (DIAAS). Since most edible legumes are mainly available in their processed forms, an interrogation of these processing methods, which could be traditional (e.g., cooking, milling, extrusion, germination, and fermentation) or based on emerging technologies (e.g., high-pressure processing (HPP), ultrasound, irradiation, pulsed electric field (PEF), and microwave), is not only critical but also necessary given the capacity of processing methods to influence protein digestibility. Therefore, this timely and important review discusses how each of these processing methods affects legume seed digestibility, examines the potential for improvements, highlights the challenges posed by antinutritional factors, and suggests areas of focus for future research.

Some Insect Species Are Good-Quality Protein Sources for Children and Adults: Digestible Indispensable Amino Acid Score (DIAAS) Determined in Growing Pigs

BACKGROUND

Insect species are suitable for farming as "mini livestock" for human and animal consumption. It is important to assess the protein quality of relevant species to understand the potential of these novel protein sources in future sustainable food systems.

OBJECTIVES

We aimed to determine the protein quality of 5 insect species-lesser mealworm (LMW), yellow mealworm, house cricket (HC), banded cricket (BC), and black soldier fly-using the digestible indispensable amino acid score (DIAAS) in a pig model.

METHODS

Five diets were formulated to contain 10% insect crude protein (CP). A nitrogen (N)-free diet was included to estimate endogenous losses. In a 6 × 6 Latin square design, 6 ileal cannulated crossbred [Duroc × (Danish Landrace × Yorkshire)] male pigs with an initial body weight of 35 ± 2 kg were fed the 6 diets. Each diet was fed for 1 wk over 6 wk. Ileal digesta were collected for 8 h on days 5 and 7 each week. Analyzed CP, amino acid (AA) contents, and calculated values of standardized ileal digestibility for CP and AAs were used to assess the DIAAS of each insect.

RESULTS

The DIAAS for young children aged 6 mo-3 y and for older children, adolescents, and adults identified sulfur AAs (cysteine + methionine) as the first limiting AA in all 4 species of cricket and mealworm. For young children, both cricket species had DIAASs > 75 and for older children, adolescents, and adults both cricket species and LMW had DIAASs > 75.

CONCLUSIONS

Both cricket species (HC and BC) are classified as good-quality protein sources for young children aged 6 mo-3 y and for older children, adolescents, and adults. One mealworm species, LMW, is a good-quality protein source for older children, adolescents, and adults.

Protein Quality in Perspective: A Review of Protein Quality Metrics and Their Applications

For design of healthy and sustainable diets and food systems, it is important to consider not only the quantity but also the quality of nutrients. This is particularly important for proteins, given the large variability in amino acid composition and digestibility between dietary proteins. This article reviews measurements and metrics in relation to protein quality, but also their application. Protein quality methods based on concentrations and digestibility of individual amino acids are preferred, because they do not only allow ranking of proteins, but also assessment of complementarity of protein sources, although this should be considered only at a meal level and not a diet level. Measurements based on ileal digestibility are preferred over those on faecal digestibility to overcome the risk of overestimation of protein quality. Integration of protein quality on a dietary level should also be done based on measurements on an individual amino acid basis. Effects of processing, which is applied to all foods, should be considered as it can also affect protein quality through effects on digestibility and amino acid modification. Overall, protein quality data are crucial for integration into healthy and sustainable diets, but care is needed in data selection, interpretation and integration.

Pistachio Nuts (Pistacia vera L.): Production, Nutrients, Bioactives and Novel Health Effects

Epidemiological and clinical studies have indicated positive outcomes related to tree nut consumption. Here, we review the production, nutrient, phytochemical composition and emerging research trends on the health benefits of pistachio nuts (Pistacia vera L.). Pistachios are a good source of protein, fiber, monounsaturated fatty acids, minerals and vitamins, as well as carotenoids, phenolic acids, flavonoids and anthocyanins. Polyphenols in pistachios are important contributors to the antioxidant and anti-inflammatory effect, as demonstrated in vitro and in vivo through animal studies and clinical trials. The antimicrobial and antiviral potential of pistachio polyphenols has also been assessed and could help overcome drug resistance. Pistachio consumption may play a role in cognitive function and has been associated with a positive modulation of the human gut microbiota and beneficial effects on skin health. Pistachio polyphenol extracts may affect enzymes involved in glucose regulation and so type 2 diabetes. Taken together, these data demonstrate the health benefits of including pistachios in the diet. Further studies are required to investigate the mechanisms involved.

Plant-based snacking: research and practical applications of pistachios for health benefits

Pistachio nuts are a nutrient-dense source of good quality plant protein, commonly consumed as a minimally processed snack food or ingredient. The present paper is based on a symposium held during the 13th FENS (Federation of European Nutrition Societies) 2019 conference in Dublin that explored recent research and practical applications of pistachios as a plant-based snack, in particular, for appetite control and healthy weight management; and for glycaemic control during pregnancy. Individual nut types, whilst similar in nutritional composition, have unique characteristics which may have a significant impact on potential health effects. Recognising this, the further purpose here is to explore future research needs for pistachios, based on work completed to date and the discussion that ensued among researchers at this event, in order to advance the full scope of health benefits from pistachios, in particular, taking into account of both sustainability and nutritional health.

Brief Research Report: Estimation of the Protein Digestibility-Corrected Amino Acid Score of Defatted Walnuts

Introduction: Walnuts are considered a good source of essential fatty acids, which is unique among tree nuts. Walnuts are also composed of about 10–15% protein, but the quality of this protein has not been evaluated. Pistachios and almonds have been evaluated for their protein content using a protein digestibility-corrected amino acid score (PDCAAS), but it is unclear how the quality of protein in walnuts relates to that in other commonly consumed tree nuts. The objective of this study was to substantiate the protein quality of walnuts by determining their PDCAAS.

Methods: A small, 10-day dietary intervention trial was conducted using male Sprague-Dawley rats (n = 8, 4 per group) with two diets: a nitrogen-free diet and a diet containing protein exclusively from defatted walnuts. Feed intake and fecal output of nitrogen were measured to estimate the true protein digestibility, and the amino acid compositions of walnuts compared to child and adult populations were used to calculate amino acid scores (AAS) and PDCAAS.

Results: The true protein digestibility score of raw walnuts was calculated to be 86.22%. Raw walnuts contained 15.6 g protein/g walnut with AAS of 0.45 and 0.63 for children aged 6 months to 3 years and 3–10 years, respectively. For each population, a PDCAAS of 39 and 46% was calculated, respectively, using a protein conversion constant of 5.30. Using a protein constant of 6.25, a PDCAAS of 39% (6 months - 3 years) or 46% (3-10 years) was calculated.

Conclusions: This is the first known assessment of the PDCAAS of walnuts. Like almonds, they appear to have a low-to-moderate score, indicating they are not a quality source of protein.

Digestible indispensable amino acid score (DIAAS) is greater in animal-based burgers than in plant-based burgers if determined in pigs

PURPOSE

Determine digestible indispensable amino acid score (DIAAS) for animal- and plant-based burgers and test the hypothesis that DIAAS calculated for a burger and a burger bun is additive in a combined meal.

METHODS

Ten ileal cannulated gilts were fed experimental diets for six 9-d periods with ileal digesta being collected on d 8 and 9 of each period. Six diets contained a burger (i.e., 80% lean beef, 93% lean beef, 80% lean pork, Impossible Burger, or Beyond Burger) or a burger bun as the sole source of crude protein and amino acids. Three additional diets were based on a combination of the bun and 80% beef, pork, or Impossible Burger. A nitrogen-free diet was also used. The DIAAS for all ingredients and mixed meals was calculated for children from 6 months to 3 years and for individuals older than 3 years, and DIAAS for combined meals was predicted from individual ingredient DIAAS.

RESULTS

The 93% lean beef and the pork burgers had greater (P < 0.05) DIAAS than the plant-based burgers for both age groups. The 80% lean beef burger had greater (P < 0.05) DIAAS than the plant burgers for children from 6 months to 3 years, and greater (P < 0.05) DIAAS than the Beyond Burger for individuals older than 3 years. There were no differences between the measured and predicted DIAAS.

CONCLUSIONS

The protein quality of animal-based burgers is greater than that of plant-based burgers. However, for individuals older than 3 years, the Impossible Burger has comparable protein quality to the 80% lean beef burger. The DIAAS obtained from individual foods is additive in mixed meals.

In vitro gastrointestinal digestion and simulated colonic fermentation of pistachio nuts determine the bioaccessibility and biosynthesis of chronobiotics

Chronodisruption leads to obesity and other metabolic disorders that can be alleviated by food-derived potential chronobiotics, such as phytomelatonin (PMT), phenolic compounds (PCs) and dietary fiber rich pistachios. Pistachios with (PN + SC) or without (PN) the seed coat were investigated for their in vitro chronobiotic potential since they are one of the main reported PMT sources. Consequently we evaluated the bioaccessibility, permeability, and biosynthesis of pistachio chronobiotics, particularly PMT, during gastrointestinal and colonic fermentation. The maximum in vitro bioaccessibility and apparent permeability (efflux-prone) of PCs, flavonoids and PMT were sample-specific [∼1.3% (both), 27 and 3.4% (PN + SC)], but additional amounts (flavonoids > PCs > PMT) were released under simulated colonic conditions. Short-chain fatty acids (SCFAs; 38 mM; >50% butyrate, PN + SC > PN) and some metabolites (e.g., indole, benzaldehyde, phenolic acids, and aliphatic/aromatic hydrocarbons) were detected depending on the sample. The predominant pistachio butyrate production during in vitro colonic fermentation can improve chronodisruption and benefit obese individuals. Pistachio's digestion increases the bioaccessibility and intestinal permeability of potential chronobiotics (PMT and PCs) and the biosynthesis of colonic metabolites (SCFAs, among others) also with chronobiotic potential.

A comprehensive study of raw and roasted macadamia nuts: Lipid profile, physicochemical, nutritional, and sensory properties

Macadamia nuts have high nutritional value and positive health attributes. Changes to the composition and availability of these compounds during roasting contribute to product quality. In this study, changes to the chemical composition of lipids (fatty acids, triglycerides, and free fatty acids) and other phytochemicals were analyzed, and a sensory evaluation was carried out of two major varieties of macadamia nuts planted in China, after roasting. Only small changes in fatty acid (FA) content and a slight decrease in total triglycerides (TAGs) were observed after roasting. The free fatty acid (FFA) content and the peroxide value were increased by roasting. The total available polyphenol content increased by 25.6% and the oxidative stability index of kernels increased by 21.6%. The sensory scores for taste and aroma were doubled by roasting. Overall, the sensory, nutritional quality, and oxidative stability of roasted macadamia nuts were greatly improved, compared with raw nuts.

Determinants of amino acid bioavailability from ingested protein in relation to gut health

PURPOSE OF REVIEW

The current review provides an update on the recent research developments regarding amino acid bioavailability in conditions of both good health and gut disorders.

RECENT FINDINGS

Determination of amino acid bioavailability is complex and invasive. Minimally invasive methods using stable isotopes have been developed for humans. Data were collected in different models - humans, pigs and rats with various procedures - leading to interstudy variability. They mainly focused on either plant protein or the effect of food processing on animal protein. Plant protein in their original food matrix (legumes, grains, nuts) are generally less digestible (about 80%) than animal protein (meat, egg, milk; about 93%). Food processing has a limited impact on animal protein but its effect might be higher on plant protein. Few studies have documented the effect of gut disorders on protein digestibility, except in gastric bypass where paradoxical effects were reported. Data are needed to identify the amplitude of protein malabsorption in diseases such as inflammatory bowel disease or environmental enteric dysfunction.

SUMMARY

The past 5 years have seen a renewed interest in amino acid bioavailability in view of assessing protein quality to support current shifts in protein sourcing. Methodological developments have been performed and several studies have reported values in various models. The question of protein digestibility in gut disorders remains poorly addressed.