The extraction of buckwheat protein and its interaction with kappa-carrageenan: Textural, rheological, microstructural, and chemical properties.

Current plant-based foods use plant proteins as a key structuring and texturing ingredient. The use of water for extraction can replace conventional protein extraction methods. Water extraction of protein is environmentally friendly and could prevent the loss of protein functionality due to extreme pH changes. This study demonstrates an aqueous extraction method, coupled with ultrasound as pre-treatment, to obtain buckwheat protein (BWPE) and assess its gelling property and composited gel with kappa-carrageenan (k-carr). Textural and rheological analyses showed that the hardness and storage modulus of the composited gel containing 1 % w/w BWPE and 1 % w/w k-carr was 4.2-fold and 100-fold, respectively, higher than k-carr gel at 1 % w/w. Light microscopy showed a mixed bi-continuous gel system, with k-carr reinforcing the protein gel network. Besides volume exclusion effects, chemical bond and FTIR analyses revealed that adding k-carr to BWPE altered the protein's secondary structure and mediated protein denaturation during heating. This results in greater ß-sheet content, which creates a more organised gel structure. These results demonstrated that ultrasound-assisted water-extracted BWPE, together with varying concentrations of k-carr, can be used to develop composited gels of tailorable textural and rheological properties to suit different food applications.

Gut microbiome responses to dietary intervention with hypocholesterolemic vegetable oils.

Hypercholesterolemia is becoming a problem with increasing significance. Dietary vegetable oils may help to improve this condition due to presence of phytonutrients with potentially synergistic cholesterol-lowering effects. The objective of this 8-week double-blinded randomized clinical trial was to investigate the effects of consuming 30 g of two different blended cooking oils, rich in omega-3 alpha-linolenic acid and phytonutrients, or refined olive oil on the intestinal microbiota in 126 volunteers with borderline hypercholesterolemia. Multi-factor analysis of relationships between the gut microbiota composition at various taxonomic ranks and the clinical trial parameters revealed the association between beneficial effects of the dietary intervention on the blood lipid profile with abundance of Clostridia class of the gut microbiota. This microbiota feature was upregulated in the course of the dietary intervention and associated with various plasma markers of metabolic health status, such as Triglycerides, Apolipoprotein B and Total Cholesterol to HDL ratio in a beneficial way. The relative abundance of a single species-Clostridium leptum-highly increased during the dietary intervention in all the three study groups. The oil blend with the highest concentration of omega-3 PUFA is associated with faster and more robust responses of the intestinal microbiota, including elevation of alpha-diversity. Butyrate production is being discussed as a plausible process mediating the observed beneficial influence on the plasma lipid profile. Causal mediation analysis suggested that Clostridium genus rather than the higher rank of the phylogeny-Clostridia class-may be involved in the diet-induced improvements of the blood lipid profile.

Branched Chain Amino Acid Supplementation to a Hypocaloric Diet Does Not Affect Resting Metabolic Rate but Increases Postprandial Fat Oxidation Response in Overweight and Obese Adults after Weight Loss Intervention.

BACKGROUND: Branched chain amino acids (BCAA) supplementation is reported to aid in lean mass preservation, which may in turn minimize the reduction in resting metabolic rate (RMR) during weight loss. Our study aimed to examine the effect of BCAA supplementation to a hypocaloric diet on RMR and substrate utilization during a weight loss intervention. METHODS: A total of 111 Chinese subjects comprising 55 males and 56 females aged 21 to 45 years old with BMI between 25 and 36 kg/m2 were randomized into three hypocaloric diet groups: (1) standard-protein (14%) with placebo (CT), (2) standard-protein with BCAA, and (3) high-protein (27%) with placebo. Indirect calorimetry was used to measure RMR, carbohydrate, and fat oxidation before and after 16 weeks of dietary intervention. RESULTS: RMR was reduced from 1600 ± 270 kcal/day to 1500 ± 264 kcal/day (p < 0.0005) after weight loss, but no significant differences in the change of RMR, respiratory quotient, and percentage of fat and carbohydrate oxidation were observed among the three diet groups. Subjects with BCAA supplementation had an increased postprandial fat (p = 0.021) and decreased postprandial carbohydrate (p = 0.044) oxidation responses compared to the CT group after dietary intervention. CONCLUSIONS: BCAA-supplemented standard-protein diet did not significantly attenuate reduction of RMR compared to standard-protein and high-protein diets. However, the postprandial fat oxidation response increased after BCAA-supplemented weight loss intervention.

Branched-Chain Amino Acid Supplementation Does Not Preserve Lean Mass or Affect Metabolic Profile in Adults with Overweight or Obesity in a Randomized Controlled Weight Loss Intervention.

BACKGROUND: Branched-chain amino acid (BCAA) supplementation has been shown to increase muscle mass or prevent muscle loss during weight loss. OBJECTIVE: We aimed to investigate the effects of a BCAA-supplemented hypocaloric diet on lean mass preservation and insulin sensitivity. METHODS: A total of 132 Chinese adults (63 men and 69 women aged 21-45 y, BMI 25-36 kg/m2) were block randomly assigned by gender and BMI into 3 hypocaloric diet (deficit of 500 kcal/d) groups: standard-protein (14%) with placebo (control, CT) or BCAA supplements at 0.1 g · kg-1 body weight · d-1 (BCAA) or high-protein (27%) with placebo (HP). The subjects underwent 16 wk of dietary intervention with provision of meals and supplements, followed by 8 wk of weight maintenance with provision of supplements only. One-way ANOVA analysis was conducted to analyze the primary (lean mass and insulin sensitivity) and secondary outcomes (anthropometric and metabolic parameters) among the 3 groups. Paired t-test was used to analyze the change in each group. RESULTS: The 3 groups demonstrated similar significant reductions in body weight (7.97%), fat mass (13.8%), and waist circumference (7.27%) after 16 wk of energy deficit. Lean mass loss in BCAA (4.39%) tended to be lower than in CT (5.39%) and higher compared with HP (3.67%) (P = 0.06). Calf muscle volume increased 3.4% in BCAA and intramyocellular lipids (IMCLs) decreased in BCAA (17%) and HP (18%) (P < 0.05) over 16 wk. During the 8 wk weight maintenance period, lean mass gain in BCAA (1.03%) tended to be lower compared with CT (1.58%) and higher than in HP (-0.002%) (P = 0.04). Lean mass gain differed significantly between CT and HP (P = 0.03). Insulin sensitivity and metabolic profiles did not differ among the groups throughout the study period. CONCLUSIONS: BCAA supplementation does not preserve lean mass or affect insulin sensitivity in overweight and obese adults during weight loss. A higher protein diet may be more advantageous for lean mass preservation.

Two Blends of Refined Rice Bran, Flaxseed, and Sesame Seed Oils Affect the Blood Lipid Profile of Chinese Adults with Borderline Hypercholesterolemia to a Similar Extent as Refined Olive Oil.

BACKGROUND: Individual vegetable oils have a characteristic fatty acids (FA) composition and unique phytonutrient profiles, enabling formulation of oil blends that may have health-promoting effects. OBJECTIVE: The primary objective of this study was to investigate effects of 2 oil blends made with refined rice bran, flaxseed, and sesame oils, with distinct monounsaturated to saturated FA, polyunsaturated to saturated FA, and omega-3 (n-3) to omega-6 FA ratios and different phytonutrient concentrations on blood lipid profile, compared with refined olive oil as a control. The secondary outcomes were other markers of cardiometabolic health. METHODS: A parallel-design, randomized controlled trial compared consumption of 30 g of allocated intervention oil per day for a period of 8 wk. The study recruited 143 borderline hypercholesterolemic (LDL cholesterol: 3.06-4.51 mmol/L) Chinese volunteers between 50 and 70 y old and with a BMI (kg/m2) ≤27.5. All outcomes were measured every 2 wk, and the time × treatment interactions and the main effects of treatment and time were analyzed using an intention-to-treat approach. RESULTS: Compared with baseline (week 0), there were significant reductions during the post-intervention time points in serum total cholesterol (-3.47%; P < 0.0001), LDL cholesterol (-4.16%; P < 0.0001), triglycerides (-10.3%; P < 0.0001), apoB (-3.93%; P < 0.0001), total to HDL-cholesterol (-3.44%; P < 0.0001) and apoB to apoA1 (-3.99%; P < 0.0001) ratios, systolic and diastolic blood pressures (-3.32% and -3.16%, respectively; both P < 0.0001), and serum glucose (-1.51%; P < 0.05) and a small but significant increase in body weight (+0.7%; P < 0.001) for all 3 intervention oils but no effects of intervention on HDL-cholesterol or apoA1 concentration. No significant effects of treatment or time × treatment interactions were found. CONCLUSIONS: Using blended vegetable oils that are extensively consumed in Asia, this study found that specific oil blends can improve blood lipid profile and other cardiometabolic parameters, to a similar extent as refined olive oil, in Chinese adults with borderline hypercholesterolemia. This trial is registered at www.clinicaltrials.gov as NCT03964857.

Folate and Vitamin B-12 Status Is Associated With Bone Mineral Density and Hip Strength of Postmenopausal Chinese-Singaporean Women.

The role of micronutrients such as folate and vitamin B-12 in bone quality has been widely studied with conflicting results. Ethnicity seems to play a large role on nutrient intake, as diet varies across cultures. In this study, we examined the relationships of BMD, proximal femur strength, and bone resorption with plasma folate and vitamin B-12 in a cohort of 93 healthy postmenopausal women of Chinese-Singaporean descent. The parameters examined were areal (aBMD) and volumetric BMD (vBMD) of the proximal femur and the third lumbar vertebra (L3), total body aBMD, proximal femur bending, compressive and impact strength indices (composite strength indices) and circulating levels of C-telopeptide of type I collagen. Eighteen participants (19.4%) had aBMD in the osteoporotic range (osteoporosis group), 59 (63.4%) in the osteopenic range (osteopenia group), and the remaining 16 (17.2%) in the normal range (normal BMD group). Circulating folate levels were significantly higher in the normal BMD group compared with the osteoporosis group. Using linear regression analysis, we found that overall, aBMD and vBMD are positively associated with folate concentrations, whereas composite strength indices were positively associated with vitamin B-12 concentrations. These findings support the existing literature and suggest a link between levels of circulating folate/vitamin B-12 and BMD/bone strength in the cohort examined. Further investigation is needed to examine if individuals with inadequate circulating levels of these nutrients could decrease their risk for fragility fractures through better nutrition or vitamin supplementation. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Dose-Dependent Increase in Unconjugated Cinnamic Acid Concentration in Plasma Following Acute Consumption of Polyphenol Rich Curry in the Polyspice Study.

Spices that are rich in polyphenols are metabolized to a convergent group of phenolic/aromatic acids. We conducted a dose-exposure nutrikinetic study to investigate associations between mixed spices intake and plasma concentrations of selected, unconjugated phenolic/aromatic acids. In a randomized crossover study, 17 Chinese males consumed a curry meal containing 0 g, 6 g, and 12 g of mixed spices. Postprandial blood was drawn up to 7 h at regular intervals and plasma phenolic/aromatic acids were quantified via liquid chromatography tandem mass spectrometry (LC-MS/MS). Cinnamic acid (CNA, p < 0.0001) and phenylacetic acid (PAA, p < 0.0005) concentrations were significantly increased with mixed spices consumption, although none of the other measured phenolic/aromatic acids differ significantly between treatments. CNA displayed a high dose-exposure association (R² > 0.8, p < 0.0001). The adjusted mean area under the plasma concentration-time curve until 7 h (AUC0⁻7 h) for CNA during the 3 increasing doses were 8.4 ± 3.4, 376.1 ± 104.7 and 875.7 ± 291.9 nM.h respectively. Plasma CNA concentration may be used as a biomarker of spice intake.

Co-Ingestion of Rice Bran Soymilk or Plain Soymilk with White Bread: Effects on the Glycemic and Insulinemic Response.

The regular consumption of soy products is associated with inverse incidence of type 2 diabetes, and there has been an increasing interest in the glycemia reducing potential of rice bran and its components. In this study, we investigated whether consuming soymilk with the addition of rice bran (fiber) can reduce the glycemic response of a carbohydrate meal. Seventeen healthy Asian men (BMI: 18.5-29 kg/m²) participated in this randomized crossover trial. On four occasions, they consumed white bread (two times) and white bread with two different soymilks differing in protein and rice bran content. Blood samples were taken to measure glucose and insulin response over a period of 3 hours. Taking the glycemic index (GI) value of white bread as a reference value of 100, the GI of white bread when co-ingested with rice bran soymilk (RBS) was 83.1 (±7.7) and sugar-free soymilk (SFS) was 77.5 (±10.1), both were lower than white bread (p < 0.05). The insulin response of both soymilk treatments was similar to white bread (p > 0.05). The glucose/insulin ratio of RBS and SFS were respectively 43.1 (± 6.1) and 60.0 (± 17.0) and were lower (p < 0.05) than white bread (123.5 ± 21.1) during the first 30 min. In conclusion, co-ingestion of low amounts of soy protein with a carbohydrate meal stimulated early-phase insulin secretion and thereby increased blood glucose clearance effectiveness. Furthermore, rice bran-fortified soymilk reduced the glycemic response similarly to soymilk with a greater dose of soy protein. Rice bran and its components offer therapeutic potential for glycemic and insulinemic control.

Acute effect of Clitoria ternatea flower beverage on glycemic response and antioxidant capacity in healthy subjects: a randomized crossover trial.

BACKGROUND: Clitoria ternatea L., a natural food-colorant containing anthocyanin, demonstrated antioxidant and antihyperglycemic activity. The aim of this study was to determine the effects of Clitoria ternatea flower extract (CTE) on postprandial plasma glycemia response and antioxidant status in healthy men. METHODS: In a randomized, crossover study, 15 healthy men (ages 22.53 ± 0.30 years; with body mass index of 21.57 ± 0.54 kg/m2) consumed five beverages: (1) 50 g sucrose in 400 mL water; (2) 1 g CTE in 400 mL of water; (3) 2 g CTE in 400 mL of water; (4) 50 g sucrose and 1 g CTE in 400 mL of water; and (5) 50 g sucrose and 2 g CTE in 400 mL of water. Incremental postprandial plasma glucose, insulin, uric acid, antioxidant capacities and lipid peroxidation were measured during 3 h of administration. RESULTS: After 30 min ingestion, the postprandial plasma glucose and insulin levels were suppressed when consuming sucrose plus 1 g and 2 g CTE. In addition, consumption of CTE alone did not alter plasma glucose and insulin concentration in the fasting state. The significant increase in plasma antioxidant capacity (ferric reducing ability of plasma (FRAP), oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (TEAC), and protein thiol) and the decrease in malondialdehyde (MDA) level were observed in the subjects who received 1 g and 2 g CTE. Furthermore, consumption of CTE protected sucrose-induced reduction in ORAC and TEAC and increase in plasma MDA. CONCLUSIONS: These findings suggest that an acute ingestion of CTE increases plasma antioxidant capacity without hypoglycemia in the fasting state. It also improves postprandial glucose, insulin and antioxidant status when consumed with sucrose. TRIAL REGISTRATION: Thai Clinical Trials Registry: TCTR20170609003 . Registered 09 September 2017. 'retrospectively registered'.

Capsinoids activate brown adipose tissue (BAT) with increased energy expenditure associated with subthreshold 18-fluorine fluorodeoxyglucose uptake in BAT-positive humans confirmed by positron emission tomography scan.

Background: Capsinoids are reported to increase energy expenditure (EE) via brown adipose tissue (BAT) stimulation. However, imaging of BAT activation by capsinoids remains limited. Because BAT activation is a potential therapeutic strategy for obesity and related metabolic disorders, we sought to prove that capsinoid-induced BAT activation can be visualized by 18-fluorine fluorodeoxyglucose (18F-FDG) positron emission tomography (PET). Objective: We compared capsinoids and cold exposure on BAT activation and whole-body EE. Design: Twenty healthy participants (8 men, 12 women) with a mean age of 26 y (range: 21-35 y) and a body mass index (kg/m2) of 21.7 (range: 18.5-26.0) underwent 18F-FDG PET and whole-body calorimetry after ingestion of 12 mg capsinoids or ≤2 h of cold exposure (∼14.5°C) in a crossover design. Mean standardized uptake values (SUVs) of the region of interest and BAT volumes were calculated. Blood metabolites were measured before and 2 h after each treatment. Results: All of the participants showed negligible 18F-FDG uptake post-capsinoid ingestion. Upon cold exposure, 12 participants showed avid 18F-FDG uptake into supraclavicular and lateral neck adipose tissues (BAT-positive group), whereas the remaining 8 participants (BAT-negative group) showed undetectable uptake. Capsinoids and cold exposure increased EE, although cold induced a 2-fold increase in whole-body EE and higher fat oxidation, insulin sensitivity, and HDL cholesterol compared with capsinoids. Conclusions: Capsinoids only increased EE in BAT-positive participants, which suggests that BAT mediates EE evoked by capsinoids. This implies that capsinoids stimulate BAT to a lesser degree than cold exposure as evidenced by 18F-FDG uptake below the presently accepted SUV thresholds defining BAT activation. This trial was registered at www.clinicaltrials.gov as NCT02964442.

Dietary fat and carbohydrate quality have independent effects on postprandial glucose and lipid responses.

PURPOSE: The magnitude of postprandial lipemia is influenced not only by the amount but also the type of fat and carbohydrate consumed. The aim of this study was to evaluate differences in postprandial glucose and lipid responses after a mixed meal containing low- or high-glycemic-index (GI) carbohydrate and three different types of fat varying in the degree of saturation in healthy subjects. METHODS: A randomized, controlled, single-blinded crossover study was conducted in 20 healthy Chinese men. Subjects consumed in random order six experimental isocaloric meals that differed in carbohydrate and fat quality, and contained 40 g of either saturated fat (SFA, butter), monounsaturated fat (MUFA, olive oil) or polyunsaturated fat (PUFA, grapeseed oil), and 50 g of either low-GI (basmati rice) or high-GI (jasmine rice) carbohydrate. Glucose, insulin, c-peptide, triglycerides (TG) and non-esterified fatty acids (NEFA) were measured over 4 h. RESULTS: For all substrates evaluated, there were no significant interactions between fat and carbohydrate. The incremental area under the curve (iAUC) for TG was significantly lower after the SFA and PUFA meals compared with the MUFA meal, irrespective of GI. No significant difference was found for NEFA iAUC in all treatments. Glucose, insulin and c-peptide iAUCs were significantly lower after ingestion of low-GI than high-GI meals, independent of the type of fat. CONCLUSIONS: A carbohydrate-rich meal (of either low or high GI) that contains butter or grapeseed oil results in lower postprandial TG concentrations relative to olive oil in healthy Chinese males. Glucose, insulin and c-peptide responses, however, are directly dependent on the GI of the meal and not on the degree of saturation of dietary fat. The trial was registered at clinicaltrials.gov as NCT02585427.

Polyphenol-rich curry made with mixed spices and vegetables increases postprandial plasma GLP-1 concentration in a dose-dependent manner.

Glucagon-like peptide-1 (GLP-1) plays an important role in glucose homeostasis. Evidence is emerging that dietary bioactive phytochemicals such as polyphenols can increase GLP-1 concentration in vivo. Spices are rich in polyphenols and have oro-sensory properties, both of which can increase GLP-1 secretion. We therefore investigated the effects of mixed spices intake on postprandial GLP-1 concentration. Using a randomised, controlled, dose-response crossover trial in 20 young, healthy, Chinese men, volunteers were served white rice with 3 doses of curry made with mixed spices and vegetables. These test meals were isocaloric and macronutrient matched. Plasma total GLP-1 concentrations were measured before (baseline) and for up to 3 h after the consumption of test meals. We found a significant dose dependent increase in total AUC of plasma GLP-1 concentrations, adjusted for baseline, with increasing mixed spice doses [adjusted mean (±SEM) of 10568.3 ± 1267.9, 12391.8 ± 1333.94, and 13905.1 ± 1267.6 pg ml-1.min for Dose 0 Control, Dose 1 Curry and Dose 2 Curry respectively (p = 0.019)]. Consumption of polyphenol rich mixed spices and vegetables can therefore increase in vivo GLP-1 concentration.

Effects of the physical-form and the degree-of-saturation of oil on postprandial plasma triglycerides, glycemia and appetite of healthy Chinese adults.

Ethylcellulose (EC) forms a complex oleogel network that entraps lipids. The digestibility of an oleogel is influenced by the types of oils used in its preparation. This randomised, controlled, crossover study aimed to compare lipidemic, glycemic, and appetitive responses to a test meal alone (no oil control), or to palm oil (PO, 22.25 g), rice bran oil (RBO, 22.25 g), palm oleogel (PG, 22.25 g oil + 2.75 g EC), or rice bran oleogel (RBG, 22.25 g oil + 2.75 g EC). Eighteen healthy Chinese males (age: 28 ± 6 years, weight: 65.9 ± 8.5 kg, and BMI: 21.6 ± 2.0 kg m-2) completed all test visits. The participants consumed a standard dinner and fasted overnight before attending the test session in the following morning. Blood samples were taken before the participants consumed the test meal, and subsequently at fixed intervals. Plasma was analysed for triglycerides, glucose, insulin, and non-esterified fatty acids (NEFA). Appetite sensations were also measured every 30 minutes for 360 minutes. After the test meal consumption, a significant interaction effect (repeated measures ANOVA) was found on temporal changes in triglycerides (p < 0.001). Plasma triglycerides increased significantly in both PO and RBO only, but not in oleogel test meals. PO and RBO also suppressed the rise of glucose (time × treatment effect, p = 0.011) at 20, 30 and 45 min. However, no significant differences were found between palm and rice bran oils in triglycerides and glucose. Changes in insulin, NEFA and appetite did not differ among all treatments. Transformation of oils to oleogels is a novel approach to reduce after-meal triglycerides. This trial was registered with ClinicalTrials.gov as NCT02969057.

Effect of fat type in baked bread on amylose-lipid complex formation and glycaemic response.

The formation of amylose-lipid complexes (ALC) had been associated with reduced starch digestibility. A few studies have directly characterised the extent of ALC formation with glycaemic response. The objectives of this study were to investigate the effect of using fats with varying degree of saturation and chain length on ALC formation as well as glycaemic and insulinaemic responses after consumption of bread. Healthy men consumed five test breads in a random order: control bread without any added fats (CTR) and breads baked with butter (BTR), coconut oil (COC), grapeseed oil (GRP) or olive oil (OLV). There was a significant difference in glycaemic response between the different test breads (P=0·002), primarily due to COC having a lower response than CTR (P=0·016), but no significant differences between fat types were observed. Insulinaemic response was not altered by the addition of fats/oils. Although BTR was more insulinotropic than GRP (P<0·05), postprandial ß-cell function did not differ significantly. The complexing index (CI), a measure of ALC formation, was significantly higher for COC and OLV compared with BTR and GRP (P<0·05). CI was significantly negatively correlated with incremental AUC (IAUC) of change in blood glucose concentrations over time (IAUCglucose) (r -0·365, P=0·001). Linear regression analysis showed that CI explained 13·3 % of the variance and was a significant predictor of IAUCglucose (ß=-1·265, P=0·001), but IAUCinsulin did not predict IAUCglucose. Our study indicated that a simple way to modulate glycaemic response in bread could lie in the choice of fats/oils, with coconut oil showing the greatest attenuation of glycaemic response.

Plant polyphenols to enhance the nutritional and sensory properties of chocolates.

A relatively unexplored method to enhance the sensory and nutritional properties of chocolate is to use plant polyphenols. In this study, a low cost agricultural waste product - mangosteen (Garcinia mangostana Linn.) pericarp - was added as powder in graded amounts (1%, 2% and 3%w/w) to dark and compound chocolates during the mixing stage and evaluated. The particle size distributions of the chocolates were mostly within 30 µm and the chocolates displayed a homogeneous morphology. The polyphenols (procyanidins and xanthones) in mangosteen pericarp powder were also stable to simulated chocolate processing. The 3% pericarp powder concentration significantly expanded the bioactive profile and total phenolic content (13% in dark chocolates and 50% in compound chocolates) compared to their plain counterparts without affecting sensory qualities. Such low cost plant polyphenols could enhance the bioactive and flavor profile of chocolates, especially in low cocoa content compound chocolates.

Green tea catechins reduced the glycaemic potential of bread: an in vitro digestibility study.

Green tea catechins are potent inhibitors of enzymes for carbohydrate digestion. However, the potential of developing low glycaemic index bakery food using green tea extract has not been investigated. Results of this study showed that addition of green tea extract (GTE) at 0.45%, 1%, and 2% concentration levels significantly reduced the glycaemic potential of baked and steamed bread. The average retention levels of catechins in the baked and steamed bread were 75.3-89.5% and 81.4-99.3%, respectively. Bread fortified with 2% GTE showed a significantly lower level of glucose release during the first 90 min of pancreatic digestion as well as a lower content of rapidly digested starch (RDS) content. A significantly negative correlation was found between the catechin retention level and the RDS content of bread. The potential of transforming bread into a low GI food using GTE fortification was proven to be promising.

Glycaemic index and glycaemic load of selected popular foods consumed in Southeast Asia.

The objective of the present study was to determine the glycaemic index (GI) and glycaemic load (GL) values of standard portion sizes of Southeast Asian traditional foods. A total of fifteen popular Southeast Asian foods were evaluated. Of these foods, three were soft drinks, while the other twelve were solid foods commonly consumed in this region. In total, forty-seven healthy participants (eighteen males and twenty-nine females) volunteered to consume either glucose at least twice or one of the fifteen test foods after a 10-12 h overnight fast. Blood glucose concentrations were analysed before consumption of the test food, and 15, 30, 45, 60, 90 and 120 min after food consumption, using capillary blood samples. The GI value of each test food was calculated by expressing the incremental area under the blood glucose response curve (IAUC) value of the test food as a percentage of each participant's average IAUC value, with glucose as the reference food. Among the fifteen foods tested, six belonged to low-GI foods (Ice Green Tea, Beehoon, Pandan Waffle, Curry Puff, Youtiao and Kaya Butter Toast), three belonged to medium-GI foods (Barley Drink, Char Siew Pau and Nasi Lemak), and the other six belonged to high-GI foods (Ice Lemon Tea, Chinese Carrot Cake, Chinese Yam Cake, Chee Cheong Fun, Lo Mai Gai and Pink Rice Cake). The GI and GL values of these traditional foods provide valuable information to consumers, researchers and dietitians on the optimal food choice for glycaemic control. Moreover, our dataset provides GI values of fifteen foods that were not previously tested extensively, and it presents values of foods commonly consumed in Southeast Asia.

Evaluation of antioxidant capacity of Chinese five-spice ingredients.

Phenolic compounds in spices were reportedly found to possess high antioxidant capacities (AOCs), which may prevent or reduce risk of human diseases such as cardiovascular disease, cancer and diabetes. The potential AOC of Chinese five-spice powder (consist of Szechuan pepper, fennel seed, cinnamon, star anise and clove) with varying proportion of individual spice ingredients was investigated through four standard methods. Our results suggest that clove is the major contributor to the AOC of the five-spice powder whereas the other four ingredients contribute to the flavour. For example, the total phenolic content as well as ferric reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) values increased linearly with the clove percentage in five-spice powder. This observation opens the door to use clove in other spice mixtures to increase their AOC and flavour. Moreover, linear relationships were also observed between AOC and the total phenolic content of the 32 tested spice samples.