Hard-to-cook phenomenon in common legumes: Chemistry, mechanisms and utilisation

Cookability of 24 pea accessions-determining factors and potential predictors of cooking quality

BACKGROUND

Cooking time and cooking evenness are two critical quantities when determining the cooking quality (termed cookability) of pulses. Deciphering which factors contribute to pulse cookability is important for breeding new cultivars, and the identification of potential cookability predictors can facilitate breeding efforts. Seeds from 24 morphologically diverse pea accessions were tested to identify contributing factors and potential predictors of the observed cookability using a Mattson cooker. Size- and weight-based measures were recorded, and seed-coat hardness was obtained with a penetrometer. Content of protein, starch (amylose and amylopectin), and phytate was also determined.

RESULTS

Distinct differences were found between wrinkled and non-wrinkled seeds in terms of water-absorption capacity, seed-coat hardness, and plunger-perforation speed. Potential predictive indicators of cooking time and cooking evenness were seed-coat hardness (r = 0.49 and r = 0.38), relative area gained (r = -0.59 and r = -0.8), and percentage of swelled seeds after soaking (r = -0.49 and r = -0.58), but only for non-wrinkled seeds. Surprisingly, the coefficients of variation for the profile area of both dry and swelled seeds appeared to be potential cookability predictors of all pea types (correlation coefficients around r = 0.5 and supported by principal component analysis). However, no strong correlation was observed between cookability and protein, starch, or phytate levels.

CONCLUSION

Using three types of instruments together with chemical components enabled the identification of novel cookability predictors for both cooking time and cooking evenness in pea. This study unveils the diverse quantitative aspects influencing cookability in pea. Considering both cooking time and cooking evenness, as well as seed-coat hardness, underscores the multifaceted nature of pulse cookability and offers important insights for future breeding strategies to enhance pea cultivars. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A Study of Physical, Chemical, and Sensory Characteristics of Novel Legume Dips

There is a consensus among experts and consumers that pulses are a good source of nutrients and fiber. In a traditional hummus recipe, chickpeas are the major ingredient. The present study is aimed at developing new legume dips by exchanging chickpeas (Chd) with dry green (Gld) and red lentils (Rld), dry white beans (Wbd), and dry green peas (Gpd). Presoaking, boiling, proximate composition, pH, energy, color measurement, and sensory evaluation were conducted on the dips using chickpea dip (hummus) as a control. One-way ANOVA was used to determine the differences between the dips. The results revealed significant differences in the proximate composition of legume dips. The protein content of the five samples ranged between 7.46% and 9.19%, while the values varied from 8.59% to 10.93% in fat, 3.88% to 6.54% in crude fiber, 14.48% to 15.51% in carbohydrates, 171.95 to 195.13 in energy, 1.55% to 1.76% in ash, and 63.35% to 66.90% in moisture. These variations could be attributed to the type and composition of each legume, the soaking and boiling process, and the tahini added during the preparation. pH ranged between 4.5 and 4.7. The color measurement indicated that the five legume dips could be considered bright products (high L∗>67), with a positive color valuebluered-green and yellow-. Significant differences (p ≤ 0.05) were observed in the legume dips sensory evaluation, and the red lentil dip was the most acceptable with results comparable to the chickpea dip; it was followed by the green lentil, white bean, and green pea dips. These results highlight the feasibility of commercial production of legume dip that promotes human health and gives consumers more choices.

Effect of cooking on structural changes in the common black bean (Phaseolus vulgaris var. Jamapa)

The cooking process is fundamental for bean consumption and to increase the bioavailability of its nutritional components. The study aimed to determine the effect of cooking on bean seed coat through morphological analyses with different microscopy techniques and image analyses. The chemical composition and physical properties of raw black bean (RBB) and cooked black bean (CBB) seeds were determined. The surface and cross-sectional samples were studied by Optical microscopy (OM), environmental scanning electron microscopy (ESEM), atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). The composition of samples showed significant differences after the cooking process. OM images and gray level co-occurrence matrix algorithm (GLCM) analysis indicated that cuticle-deposited minerals significantly influence texture parameters. Seed coat surface ESEM images showed cluster cracking. Texture fractal dimension and lacunarity parameters were effective in quantitatively assessing cracks on CBB. AFM results showed arithmetic average roughness (Ra) (121.67 nm) and quadratic average roughness (Rq) (149.94 nm). The cross-sectional ESEM images showed a decrease in seed coat thickness. The CLSM results showed an increased availability of lipids along the different multilayer tissues in CBB. The results generated from this research work offer a valuable potential to carry out a strict control of bean seed cooking at industrial level, since the structural changes and biochemical components (cell wall, lipids and protein bodies) that occur in the different tissues of the seed are able to migrate from the inside to the outside through the cracks generated in the multilayer structure that are evidenced by the microscopic techniques used.

Nutritional, Biochemical, and Functional Properties of Pearl Millet and Moringa oleifera Leaf Powder Composite Meal Powders

This study sought to improve pearl millet's nutritional, functional, and biochemical properties through malting and fermentation. Moringa oleifera leaf powder (MLP) was used as a fortificant. Mixture design was used to find optimal proportions for each component that yielded a high protein and or low saturated fat content. Twelve mixtures with varying ratios of fermented and malted pearl millet flour ranging between 30-65% and MLP between 5-15% were generated through I-Optimal mixture design. The mixtures were wet-cooked, freeze-dried, and analysed for protein and fat content. The data obtained were fitted to a linear mixture model, and the search for the optimum was conducted using Numerical Optimisation for maximising protein and minimising saturated fat. The linear model was suitable for explaining total protein and saturated fat variation with r2 of 0.50 and 0.51, respectively. Increasing MLP increased protein content. Two final formulations, Optimisation Solution 1 (OS1) and Optimisation Solution 2 (OS2), were generated through the optimisation process. Pearl millet's protein content increased by up to 22%, while saturated fat decreased by up to 13%; ash content increased by 75%. Polyphenol content and oxygen radical absorbance capacity increased by 80% and 25%, respectively. Final and peak viscosity were reduced by 90% and 95%, respectively.

Associations between Cardiometabolic Risk Factors and Increased Consumption of Diverse Legumes: A South African Food and Nutrition Security Programme Case Study

The programme aimed to improve selected cardiometabolic risk (CMR) variables using a nutritional intervention among farmers who reported hypertensive disorders as hindrances during agricultural activities. The intervention had two case controls (n = 103) [experimental group-EG (n = 53) and control group-CG (n = 50)] which were tracked and whose blood pressure measurements, dietary intake, blood indices for cholesterol concentration and glucose levels from pre- and post-intervention surveys after the baseline survey (n = 112) were analysed. The interval for data collection was 12 weeks (±120 days) after five legume varieties were consumed between 3 and 5 times a day, and servings were not <125 g per at least three times per week. Sixty-five per cent of farmers were above 60 years old, with mean age ranges of 63.3 (SD ± 6.3) years for women and 67.2 (SD ± 6.7) for men. The post-intervention survey revealed that EG blood results indicated nutrient improvement with p <= 0.05 for blood glucose (p = 0.003) and cholesterol (p = 0.001) as opposed to the CG. A trend analysis revealed that cholesterol (p = 0.033) and systolic blood pressure (SBP); (p = 0.013) were statistically significant when comparing genders for all study phases. Interventions focusing on legumes can improve hypertension and cardiovascular disease and fast-track the achievement of SGDs 3 and 12 through community-based programmes.

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

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

Unveiling Diversity for Quality Traits in the Indian Landraces of Horsegram [Macrotyloma uniflorum (Lam.) Verdc.]

Horsegram (Macrotyloma uniflorum [Lam.] Verdc.) is an underutilized pulse crop primarily cultivated in South Asian countries like India, Nepal, and Sri Lanka. It offers various nutraceutical properties and demonstrates remarkable resilience to both biotic and abiotic stresses. As a result, it has emerged as a promising crop for ensuring future food and nutritional security. The purpose of this study was to assess the nutritional profile of 139 horsegram germplasm lines obtained from 16 Indian states that were conserved at the National Gene Bank of India. Standard analytical methods, including those provided by the Association of Official Analytical Chemists (AOAC), were used for this investigation. The study revealed substantial variability in essential nutrients, such as protein (ranging from 21.8 to 26.7 g/100 g), starch (ranging from 26.2 to 33.0 g/100 g), total soluble sugars (TSSs) (ranging from 0.86 to 12.1 g/100 g), phenolics (ranging from 3.38 to 11.3 mg gallic acid equivalents (GAEs)/g), and phytic acid content (ranging from 1.07 to 21.2 mg/g). Noteworthy correlations were observed, including a strong positive correlation between sugars and phenols (r = 0.70) and a moderate negative correlation between protein and starch (r = -0.61) among the studied germplasm lines. Principal component analysis (PCA) highlighted that the first three principal components contributed to 88.32% of the total variability, with TSSs, phytates, and phenols emerging as the most significant contributors. The cluster analysis grouped the accessions into five clusters, with cluster III containing the accessions with the most desirable traits. The differential distribution of the accessions from north India into clusters I and III suggested a potential geographical influence on the adaptation and selection of genes. This study identified a panel of promising accessions exhibiting multiple desirable traits. These specific accessions could significantly aid quality breeding programs or be directly released as cultivars if they perform well agronomically.