Determination of Indispensable Amino Acid Digestibility of the Red Kidney Bean in Humans Using a Dual Stable Isotope Tracer Method.

BACKGROUND: Protein quality of the red kidney bean (RKB), a common source of dietary protein, has been assessed using the protein digestibility-corrected amino acid score (PDCAAS) determined in animal models using mainly oro-fecal digestibility. More recently, the FAO recommended to use digestible indispensable amino acid score (DIAAS) instead of PDCAAS but highlighted insufficient data on true ileal indispensable amino acid (IAA) digestibility of proteins because amino acids are absorbed in the ileum. OBJECTIVES: Using a recently developed dual stable isotope tracer method, we aimed to measure each IAA digestibility as representation of true ileal digestibility of the RKB, Phaseolus vulgaris, in humans consuming a typical Jamaican meal. METHODS: RKB-IAAs were intrinsically labeled by adding 2H2O to the plants. Uniformly labeled-[13C]-spirulina (standard protein) was added to a meal prepared with the labeled RKB and fed to 10 healthy adults (5 males, 5 females) in a nonrandomized trial as primed/intermittent doses to achieve a steady state IAA enrichment in plasma. Enrichment of 2H- and 13C-labeled IAA in plasma and the bean was measured by mass spectrometry. Each IAA digestibility (except tryptophan and histidine) was calculated as the ratio of plasma 2H-IAA to meal 2H-IAA divided by the ratio of plasma 13C-IAA to meal 13C-IAA adjusted for loss of 2H-atom during transamination and digestibility of spirulina. RESULTS: Adequate IAA labeling (>1000 ppm 2H excess) and plasma plateau isotopic enrichment were achieved. Mean RKB-IAA digestibility (%) was 79.4 ± 0.5, ranging from 69.0 ± 1.2 (threonine) to 85.7 ± 1.7 (lysine). CONCLUSION: The dual stable isotope tracer digestibility data are similar to published oro-fecal digestibility supporting substantial nitrogen exchange in the colon. The individual IAA digestibility is useful to derive DIAAS to replace PDCAAS. Using published RKB-IAA composition, extrapolated DIAAS was 0.63 based on the lowest score for methionine. CLINICAL TRIAL REGISTRATION: https://register. CLINICALTRIALS: gov; ID: NCT-04118517.

Relationship between Processing Method and the Glycemic Indices of Ten Sweet Potato (Ipomoea batatas) Cultivars Commonly Consumed in Jamaica.

This study investigated the effect of different traditional cooking methods on glycemic index (GI) and glycemic response of ten Sweet potato (Ipomoea batatas) cultivars commonly eaten in Jamaica. Matured tubers were cooked by roasting, baking, frying, or boiling then immediately consumed by the ten nondiabetic test subjects (5 males and 5 females; mean age of 27 ± 2 years). The GI varied between 41 ± 5-93 ± 5 for the tubers studied. Samples prepared by boiling had the lowest GI (41 ± 5-50 ± 3), while those processed by baking (82 ± 3-94 ± 3) and roasting (79 ± 4-93 ± 2) had the highest GI values. The study indicates that the glycemic index of Jamaican sweet potatoes varies significantly with the method of preparation and to a lesser extent on intravarietal differences. Consumption of boiled sweet potatoes could minimize postprandial blood glucose spikes and therefore, may prove to be more efficacious in the management of type 2 diabetes mellitus.

The role of high-density lipoproteins in reducing the risk of vascular diseases, neurogenerative disorders, and cancer.

High-density lipoprotein (HDL) is one of the major carriers of cholesterol in the blood. It attracts particular attention because, in contrast with other lipoproteins, as many physiological functions of HDL influence the cardiovascular system in favourable ways unless HDL is modified pathologically. The functions of HDL that have recently attracted attention include anti-inflammatory and anti-oxidant activities. High anti-oxidant and anti-inflammatory activities of HDL are associated with protection from cardiovascular disease. Atheroprotective activities, as well as a functional deficiency of HDL, ultimately depend on the protein and lipid composition of HDL. Further, numerous epidemiological studies have shown a protective association between HDL-cholesterol and cognitive impairment. Oxidative stress, including lipid peroxidation, has been shown to be the mediator of the pathologic effects of numerous risk factors of Alzheimer's disease. Lifestyle interventions proven to increase HDL- cholesterol levels including "healthy" diet, regular exercise, weight control, and smoking cessation have also been shown to provide neuro-protective effects. This review will focus on current knowledge of the beneficial effects of HDL-cholesterol as it relates to cardiovascular diseases, breast and lung cancers, non-Hodgkin's lymphoma, as well as its neuroprotective potential in reducing the risk of Alzheimer's disease and dementia.

Relationship between the physicochemical properties of starches and the glycemic indices of some Jamaican yams (Dioscorea spp.).

Starch granules from round leaf yellow yam (RY), Lucea yam (LY), white yam (WY), and Chinese yam (CY) grown in Jamaica were isolated and the relationship between starch amylose content, crystallinity, microscopic properties, in vitro digestibility, and the glycemic index (GI) of the tubers was investigated. The results indicate that RY had the highest amylose content (265.30 +/- 0.09 g/kg starch) while CY the lowest (111.44 +/- 0.03 g/kg starch). A corresponding variation in starch digestibility and GI was also observed, as CY which had the highest in vitro digestibility had the highest GI (21.27 +/- 0.01 and 97.42 +/- 0.62%, respectively), while RY, LY, and WY starches with low digestibility had lowest GI. Differences in the crystalline pattern of the different starches were observed, where RY, LY, and WY displayed the type B crystalline pattern while CY had the intermediate crystallite (type C).

The interplay between yam (Dioscorea sp.) starch botanical source, micromeritics and functionality in paracetamol granules for reconstitution.

A comparative investigation of the interplay between starch botanical source, micromeritics and their functionality in formulated paediatric paracetamol granules for reconstitution was conducted using starches extracted from five local yam (Dioscorea spp.) species. Significant differences were observed in the physicochemical properties of the different starches studied (p<0.05). The observed differences in paracetamol dissolution correlated well with the physicochemical properties of the starches. Granules formulated with Chinese yam and Bitter yam starches showed the fastest rate of paracetamol dissolution with T(80) of 2.2 and 2.6 min, respectively, at 2.5%w/w, and 3.75 and 4.00 min, respectively, at 10% w/w binder concentrations. Those formulated with Round leaf yellow yam starch had the slowest dissolution rate with T(80) of 4.5 and 8.75 min, respectively, at 2.5% and 10% binder concentrations. The results generally indicate a significant dependence of the rate of paracetamol dissolution from granules on starch surface tension, viscosity, swelling power and water binding capacity, particle size distribution, specific surface and porosity. These, in turn, were found to be starch botanic source-dependent suggesting careful consideration of botanic source when substituting one starch product for another in granule formulation.