Incorporation of dietary fibre-rich oyster mushroom (Pleurotus sajor-caju) powder improves postprandial glycaemic response by interfering with starch granule structure and starch digestibility of biscuit.

The purpose of this study was to determine the effects of Pleurotus sajor-caju (PSC) powder addition at 0, 4, 8 and 12% levels on the nutritional values, pasting properties, thermal characteristics, microstructure, in vitro starch digestibility, in vivo glycaemic index (GI) and sensorial properties of biscuits. Elevated incorporation levels of PSC powder increased the dietary fibre (DF) content and reduced the pasting viscosities and starch gelatinisation enthalpy value of biscuits. The addition of DF-rich PSC powder also interfered with the integrity of the starch granules by reducing the sizes and inducing the uneven spherical shapes of the starch granules, which, in turn, resulted in reduced starch susceptibility to digestive enzymes. The restriction starch hydrolysis rate markedly reduced the GI of biscuits. The incorporation of 8% PSC powder in biscuits (GI=49) could be an effective way of developing a nutritious and low-GI biscuit without jeopardizing its desirable sensorial properties.

Reduction of postprandial blood glucose in healthy subjects by buns and flatbreads incorporated with fenugreek seed powder.

PURPOSE: This study aimed to determine whether fenugreek seed powder could reduce the glycemic response and glycemic index (GI) when added to buns and flatbreads. METHODS: In a randomised, controlled crossover trial, ten healthy human subjects (five men, five women) were given 50 g glucose (reference food, twice); buns (0 and 10 % fenugreek seed powder); and flatbreads (0 and 10 % fenugreek seed powder) on six different occasions. Finger prick capillary blood samples were collected at 0, 15, 30, 45, 60, 90 and 120 min after the start of the meal. The palatability of the test meals was scored using Likert scales. RESULTS: The incremental areas under the glucose curve value of buns and flatbreads with 10 % fenugreek (138 ± 17 mmol × min/L; 121 ± 16 mmol × min/L) were significantly lower than those of 0 % fenugreek bun and flatbreads (227 ± 15 mmol × min/L; 174 ± 14 mmol × min/L, P = <0.01). Adding 10 % fenugreek seed powder reduced the GI of buns from 82 ± 5 to 51 ± 7 (P < 0.01) and to the GI of flatbread from 63 ± 4 to 43 ± 5 (P < 0.01). CONCLUSIONS: These results suggest that replacing 10 % of refined wheat flour with fenugreek seed powder significantly reduces the glycemic response and the GI of buns and flatbreads. Thus, fenugreek powder may be a useful functional ingredient to reduce postprandial glycemia.

Trigonella foenum-graecum seeds lowers postprandial blood glucose in overweight and obese individuals.

This study determined the effects of fenugreek on postprandial plasma glucose (PPG) and satiety among overweight and obese individuals. Fourteen subjects were studied in the morning after overnight fasts on four separate occasions. Glycaemic responses elicited by 50 g carbohydrate portions of white bread and jam with or without 5.5 g of fenugreek and fried rice with or without 5.5 g fenugreek were determined over 2 h. The primary endpoint was the incremental area under the plasma glucose response curve (IAUC). Adding fenugreek to both foods significantly reduced the IAUC compared to the food alone: white bread and jam, 180 ± 22 versus 271 ± 23 mmol × min/L (P = 0.001); fried rice, 176 ± 20 versus 249 ± 25 mmol × min/L (P = 0.001). Fenugreek also significantly reduced the area under the satiety curve for white bread with jam (134 ± 27 versus 232 ± 33 mm × hr, P = 0.01) and fried rice (280 ± 37 versus 379 ± 36 mm × hr, P = 0.01). It is concluded that fenugreek significantly decreased the PPG response and increased satiety among overweight and obese individuals.

Two varieties of honey that are available in Malaysia gave intermediate glycemic index values when tested among healthy individuals.

AIM: To determine the glycemic index (GI) of Malaysian wild honey and Australian honey. METHODS: Eight healthy volunteers (5 men and 3 women, aged 24-44 y, with normal BMI) were served 50 g carbohydrate portions of two varieties of honey or the reference food (glucose, tested 3 times), on separate occasions. Capillary blood glucose was measured fasting and at 15, 30, 45, 60, 90 and 120 min after the start of the test meals. The GI was calculated by expressing each subject's incremental area under the blood glucose curve (AUC) after honey as a percentage of his or her mean AUC after glucose. RESULTS: The results showed that the mean AUC of the Malaysian and Australian honeys, 174+/-19 and 158+/-16 mmolxmin/l, respectively, did not differ from each other but were significantly less than that after glucose, 259+/-15 mmolxmin/l (P<0.001). The mean GI of Malaysian wild honey, 65+/-7, did not differ from that of Australian honey, 59+/-5, but both were significantly less than the GI of glucose, 100 (P<0.001). CONCLUSIONS: We conclude that both Malaysian wild honey (GI=65+/-7) and Australian honey (GI=59+/-5) are intermediate GI foods.