1.
The effect of apparent amylose content and dietary fibre on the glycemic response of different varieties of cooked milled and brown rice.
Trinidad, TP, Mallillin, AC, Encabo, RR, Sagum, RS, Felix, AD, Juliano, BO
International journal of food sciences and nutrition. 2013;(1):89-93
Abstract
Brown rice is a good source of dietary fibre (DF) and contains higher vitamins/minerals than milled rice. The study determined the effect of amylose content (AC) and DF on glucose response (GR) from different varieties of milled and brown rice. Milled and brown rice were used as test foods. They were fed to 9-10 human volunteers containing 50 g available carbohydrate after an overnight fast. GR and the glycemic index (GI) were determined. Results found that Sinandomeng with the lowest AC had a high GI = 75, while PSBRc10 with the highest AC had a low GI = 50. Sinandomeng with a low DF had GI = 75, while its brown rice had GI = 55. Brown rice (IR64) with 23% AC and DF of 2.5 g/100 g had low GI = 51. In conclusion, the GR and GI of the different varieties of cooked milled and brown rice varied depending on its AC and DF contents.
2.
Medium light and medium roast paper-filtered coffee increased antioxidant capacity in healthy volunteers: results of a randomized trial.
Corrêa, TA, Monteiro, MP, Mendes, TM, Oliveira, DM, Rogero, MM, Benites, CI, Vinagre, CG, Mioto, BM, Tarasoutchi, D, Tuda, VL, et al
Plant foods for human nutrition (Dordrecht, Netherlands). 2012;(3):277-82
Abstract
We compared the effects of medium light roast (MLR) and medium roast (MR) paper-filtered coffee on antioxidant capacity and lipid peroxidation in healthy volunteers. In a randomized crossover study, 20 volunteers consumed 482 ± 61 ml/day of MLR or MR for four weeks. Plasma total antioxidant status (TAS), oxygen radical absorbance capacity (ORAC), oxidized LDL and 8-epi-prostaglandin F2α, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activity were measured at baseline and after the interventions. MLR had higher chlorogenic acids-(CGA; 334 mg/150 mL) and less caffeine (231 mg/150 ml) than MR had (210 and 244 mg/150 ml, respectively). MLR also had fewer Maillard reaction products (MRP) than MR had. Compared with baseline, subjects had an increase of 21 and 26 % in TAS, 13 and 13 % in CAT, 52 and 75 % in SOD, and 62 and 49 % in GPx after MLR and MR consumption (P < 0.001), respectively. ORAC increased after MLR (P = 0.004). No significant alteration in lipid peroxidation biomarkers was observed. Both coffees had antioxidant effects. Although MLR contained more CGA, there were similar antioxidant effects between the treatments. MRP may have contributed as an antioxidant. These effects may be important in protecting biological systems and reducing the risk of diseases related to oxidative stress.
3.
Transglutaminase catalysis of modified whey protein dispersions.
Clare, DA, Daubert, CR
Journal of food science. 2010;(4):C369-77
Abstract
UNLABELLED Transglutaminase (TGase) cross-linking reactions were accomplished using a heat-modified whey protein concentrate (mWPC) substrate after pH adjustment to 8. Based on earlier reports, the degree of lactosylation with respect to beta-lactoglobulin was lower in mWPC dispersions than measured in commercial whey concentrate (cWPC) protein solutions. In this study, a higher concentration of free sulfhydryl groups was detected in soluble supernatant fractions. Both factors potentially impact the availability of reactive lysine/glutaminyl residues required for TGase reactivity. The addition of 10 mM dithiothreitol (DTT) to the substrate mix, CBZ-glutaminyl glycine and hydroxylamine, revealed a 3.6-fold increase in TGase activity, likely due in part to maintenance of the catalytic cysteine residue in a reduced state. Furthermore, inclusion of DTT to mWPC dispersions significantly raised the apparent viscosity, independently of enzyme modification, while the rate of polymerization increased 2-fold based on OPA assay measurements. Limited cross-linking slightly increased the apparent viscosity, whereas extensive coupling lowered these values compared to equivalent nonenzyme-treated mWPC samples. Carbohydrate-staining revealed formation of glyco-polymers due to covalent linkages between glucosamine and mWPC proteins after TGase processing. Again, the apparent viscosity decreased after extensive enzymatic modification. Larger particles, sized 11.28 mum, were observed in the structural matrix of TGase-mWPC-fixed samples compared to 8 mum particles in control mWPC samples as viewed in scanning electron micrographs. Ultimately, the functional characteristics of TGase-mWPC ingredients may be custom-designed to deliver alternative functional attributes by adjusting the experimental reaction conditions under which catalysis is achieved. PRACTICAL APPLICATION Taken together, these results suggest that unique TGase-mWPC and/or TGase-mWPC-glucosamine ingredients may be designed to provide novel, value-added, polymeric/glyco-polymeric protein products that afford added benefit for the milk industry.
4.
A randomized, double-blind comparison of two different coffee-roasting processes on development of heartburn and dyspepsia in coffee-sensitive individuals.
DiBaise, JK
Digestive diseases and sciences. 2003;(4):652-6
Abstract
The mechanism underlying coffee-induced heartburn and dyspepsia remains poorly understood. This has led to speculation that variations in coffee processing may be important. The primary objective of this study was to determine whether a coffee brewed with coffee beans processed using conduction roasting will result in fewer symptoms of gastroesophageal reflux and dyspepsia in coffee-sensitive individuals compared to a differently processed yet otherwise similar coffee. Thirty coffee-sensitive individuals completed this single-center, randomized, double-blind, crossover study in which the symptoms of heartburn, regurgitation and dyspepsia were assessed following coffee consumption both in the fasting state and after ingestion of a standard test meal. Consumption of both coffees resulted in heartburn, regurgitation, and dyspepsia in most individuals. No significant differences in the frequency or severity of heartburn, regurgitation, or dyspepsia were demonstrated between the two coffees either in the fasting state or after the test meal. We conclude that differences in the coffee bean roasting process do not result in marked differences in coffee-induced upper gastrointestinal symptoms.