Antinutrients and digestibility (in vitro) of soaked, dehulled and germinated cowpeas

The Role of Dietary Phenolic Compounds in Protein Digestion and Processing Technologies to Improve Their Antinutritive Properties

Digestion is the key step for delivering nutrients and bioactive substances to the body. The way different food components interact with each other and with digestive enzymes can modify the digestion process and affect human health. Understanding how food components interact during digestion is essential for the rational design of functional food products. Plant polyphenols have gained much attention for the bioactive roles they play in the human body. However, their strong beneficial effects on human health have also been associated with a negative impact on the digestion process. Due to the generally low absorption of phenolic compounds after food intake, most of the consumed polyphenols remain in the gastrointestinal tract, where they then can exert inhibitory effects on enzymes involved in the degradation of saccharides, lipids, and proteins. While the inhibitory effects of phenolics on the digestion of energy-rich food components (saccharides and lipids) may be regarded as beneficial, primarily in weight-control diets, their inhibitory effects on the digestion of proteins are not desirable for the reason of reduced utilization of amino acids. The effect of polyphenols on protein digestion is reviewed in this article, with an emphasis on food processing methods to improve the antinutritive properties of polyphenols.

Personalizing protein nourishment

Proteins are not equally digestible-their proteolytic susceptibility varies by their source and processing method. Incomplete digestion increases colonic microbial protein fermentation (putrefaction), which produces toxic metabolites that can induce inflammation in vitro and have been associated with inflammation in vivo. Individual humans differ in protein digestive capacity based on phenotypes, particularly disease states. To avoid putrefaction-induced intestinal inflammation, protein sources, and processing methods must be tailored to the consumer's digestive capacity. This review explores how food processing techniques alter protein digestibility and examines how physiological conditions alter digestive capacity. Possible solutions to improving digestive function or matching low digestive capacity with more digestible protein sources are explored. Beyond the ileal digestibility measurements of protein digestibility, less invasive, quicker and cheaper techniques for monitoring the extent of protein digestion and fermentation are needed to personalize protein nourishment. Biomarkers of protein digestive capacity and efficiency can be identified with the toolsets of peptidomics, metabolomics, microbial sequencing and multiplexed protein analysis of fecal and urine samples. By monitoring individual protein digestive function, the protein component of diets can be tailored via protein source and processing selection to match individual needs to minimize colonic putrefaction and, thus, optimize gut health.

Individualistic impact of unit operations of production, at household level, on some antinutritional factors in selected cowpea-based food products

The individualistic effect of unit operations of production, at household level, on some antinutritional factors in selected cowpea-based food products (moin-moin, akara, and gbegiri) was investigated. Four cowpea types (IT93K-452-1, IT95K-499s-35, IT97K-568-18, and market sample) were used for the study, whereas the three traditional food products were produced from each of the cowpea types, respectively. The results revealed that every unit operation involved in the production of moin-moin, akara or gbegiri contributed to the overall reduction of trypsin inhibitor activity (TIA), phytic acid (PA), and tannin; though at varying degrees. In the production of moin-moin, the major contributions to the overall reduction in TIA were from steaming (64.2-72.0%), second-stage soaking (9.7-11.9%), and dehulling (9.4-10.2%). The contributions to the overall reduction in PA were from dehulling (34.0-40.4%), preliminary soaking (15.4-21.0%), and steaming (7.8-14.0%), whereas that of tannin were from dehulling (39.7-47.6%), steaming (19.6-24.7%), and preliminary soaking (9.8-15.9%). For akara production, the major contributions to TIA reduction were from deep frying (64.2-72.0%), second-stage soaking (9.7-11.9%), and dehulling (9.4-10.2%). The PA reduction was from dehulling (34.0-40.4%), preliminary soaking (15.4-21.0%), and deep frying (9.6-15.9%), whereas that of tannin reduction was from dehulling (39.7-47.6%), deep frying (20.7-25.3%), and preliminary soaking (9.8-15.9%). In the production of gbegiri, the overall reduction in TIA was contributed from pressure cooking (79.0-84.8%), preliminary soaking (5.8-11.3%), and dehulling (9.4-10.2%). The reduction in PA was contributed by dehulling (34.0-40.4%), pressure cooking (24.7-35.0%), and preliminary soaking (15.4-21.0%), whereas the overall reduction in tannin content was similarly contributed by dehulling (39.7-47.6%), pressure cooking (29.8-34.4%), and preliminary soaking (9.8-15.9%).

In vitro starch digestibility, pasting and textural properties of mung bean: effect of different processing methods

Mung bean was subjected to different processing conditions (soaking, germination, cooking and autoclaving) and their textural, pasting and in vitro starch digestibility characteristics were studied. A significant reduction in textural properties (hardness, cohesiveness, gumminess and chewiness) after cooking and autoclaving treatment of mung bean was observed. Flours made from differently processed mung bean showed significant differences (P < 0.05) in their pastin g characteristics. Peak and final viscosity were the highest for flour from germinated mung bean whereas those made from autoclaved mung bean showed the lowest value. in vitro starch digestibility of mung bean flours was assessed enzymatically using modified Englyst method and the parameters studied were readily digestible starch (RDS), slowly digestible starch (SDS), resistant starch (RS) and total starch (TS) content. Various processing treatments increased the RDS contents of mung bean, while the SDS content was found to be the highest for soaked and the lowest for the autoclaved sample. Germinated sample showed higher amount of digestible starch (RDS + SDS) as compared to raw and soaked samples. Flours from raw and soaked samples showed significantly low starch hydrolysis rate at all the temperatures with total hydrolysis of 29.9 and 31.2 %, respectively at 180 min whereas cooked and autoclaved samples showed high hydrolysis rates with 50.2 and 53.8 % of these hydrolyzing within 30 min of hydrolysis.

Modification and improvement of nutritive quality of cornpap "Ogi" with cowpea and groundnut milk

The study aimed at improving the nutritive quality of cornpap, "Ogi", the most popular infant feed in Nigeria. Milk samples of cowpea, groundnut and soyabean and their complementations with cornpap were assessed chemically, organoleptically and anthropometrically. The protein contents of milk from cowpea, groundnut and soyabean were 1.18, 1.6, and 1.23% respectively. On separate complementation of the milk sources with cornpap, the low protein content of "ogi" was increased from 0.3% to 2.79% with cowpea; 3.0% with groundnut and 3.64% with soyabean. The fat content of the complementary feeds also increased remarkably. The anthropometric study revealed that there were significant differences P = 0.001 between the mean weight of children aged 13 to 18 (92 +/- 1.2) and 19 to 24 months (9.9 +/- 1.3) who were fed the three sources of milk with cornpap, and the control group of the same age groups (8.5 + 1.5; 9.3 + 1.11) who received nutrition education and no complementary feeds. Of the three sources of milk, groundnut milk was ranked as the most likeable, the easiest to prepare and the least costly by the nursing mothers. This study has shown that some of the deep rooted cultural food taboos that prohibit locally available and nutritious feeds to infants could be changed through practical food demonstrations.