Juscelino Tovar

Food properties affecting the digestion and absorption of carbohydrates

Carbohydrate foods differ considerably in their effects on postprandial glucose and insulin responses. Qualitative differences among starchy foods are particularly intriguing because of the dominance of starch in human diets. This paper focuses on food properties in cereal (eg, pasta, bread, Arepas, and porridge) and legume products (eg, red kidney beans and lentils) that affect metabolic responses to starch. Studies in healthy subjects have found that postprandial blood glucose and insulin responses are greatly affected by food structure. Any process that disrupts the physical or botanical structure of food ingredients will increase the plasma glucose and insulin responses. The glycemic responses to bread products were reduced by the use of ingredients with an intact botanical or physical structure or a high amylose content or by enrichment with viscous dietary fiber. However, the important of a moderate increase in the amylose-amylopectin ratio and the naturally occurring levels of viscous cereal fiber is less clear. The rate of starch digestion in vitro was shown to be a key determinant of metabolic responses to most products. Assuming the sample preparation mimics chewing, in vitro enzymic procedures can be used to facilitate ranking. One such procedure, based on chewed rather than artificially disintegrated products, was recently developed and correlates well with glycemic and insulinemic indices for several starchy foods.

Effect of Storage Time on In Vitro Digestibility and Resistant Starch Content of Nixtamal, Masa, and Tortilla

ABSTRACT Nixtamal, masa, and tortilla samples were stored for 24–96 hr and their chemical composition, retrogradation, and in vitro starch digestibility features were evaluated. Ash and fat contents in the three products were smaller than in the original corn sample, but protein levels were higher, all in accordance with previous studies. In general, a minor decrease in available starch (AS) content was observed with storage time. Masa showed the greatest AS values, followed by tortilla and nixtamal. Tortilla presented slightly higher retrograded resistant starch (RS3) values (1.1–1.8%, dmb) than masa (0.7–0.9%) and nixtamal (0.7–0.8%) and only minor increases were observed after 24 hr of storage, suggesting that retrogradation phenomenon in these samples takes place very rapidly and is more pronounced in the final product (tortilla). The development of RS3 explains the observed decrease in AS. Higher total resistant starch values were found in all samples at a range of 2.1–2.6% for nixtamal and masa, and...

Cell walls limit in vitro protein digestibility in processed legume seeds

Abstract Legume seeds were treated in various ways, e.g. cooking applied either before or after milling, in order to obtain flours with different microstructural properties. In vitro protein digestibility was assessed by a pepsin/pancreatin index. In all cases digestibility was enhanced by cooking, although final values varied depending on the flour preparation procedure. Cooked and milled seeds, which retained intact cell walls, showed lower digestibility indices (58–72%) than sonicated or milled/cooked preparations devoid of such structures (77–89%). Results suggest that naturally occurring physical barriers, such as cell walls, may reduce the bioavailability of legume proteins.

Fiber Concentrate from Orange (Citrus sinensis L.) Bagase: Characterization and Application as Bakery Product Ingredient

Orange is a tropical fruit used in the juice industry, yielding important quantities of by products. The objective of this work was to obtain a dietary fiber-rich orange bagasse product (DFROBP), evaluate its chemical composition and its use in the preparation of a bakery product (muffin). Muffins containing two different levels of DFROBP were studied regarding chemical composition, in vitro starch digestibility, predicted glyceamic index and acceptability in a sensory test. DFROBP showed low fat and high dietary fiber contents. The soluble and insoluble dietary fiber fractions were balanced, which is of importance for the health beneficial effects of fiber sources. DFROBP-containing muffins showed the same rapidly digestible starch content as the reference muffin, whilst the slowly digestible starch level increased with the addition of DFROBP. However, the resistant starch content decreased when DFROBP increased in the muffin. The addition of DFROBP to muffin decreased the predicted glyceamic index, but no difference was found between the muffins prepared with the two DFROBP levels. The sensory score did not show difference between control muffin and that added with 10% of DFROBP. The addition of DFROBP to bakery products can be an alternative for people requiring low glyceamic response.

In vitro fermentability and antioxidant capacity of the indigestible fraction of cooked black beans (Phaseolus vulgaris L.), lentils (Lens culinaris L.) and chickpeas (Cicer arietinum L.).

BACKGROUND Pulses represent an important source of protein, as well as digestible and indigestible carbohydrates. Little information is available on the indigestible carbohydrates and antioxidant capacity of legume seeds. The cooked seeds of three pulses (black bean, chickpea and lentil) were evaluated for their indigestible fraction (IF), polyphenols content, antioxidant capacity and in vitro fermentability, including short-chain fatty acid production. RESULTS The insoluble indigestible fraction (IIF) was higher than the soluble counterpart (soluble indigestible fraction, SIF). The SIF value was highest in black beans, while no difference was observed between chickpeas and lentils. Black beans and lentils had higher polyphenols content than chickpeas. The IF of black beans exhibited the lowest and chickpeas the highest associated polyphenols content. Condensed tannins were retained to some extent in the IF that exhibited significant antioxidant capacity. The total IF of the three pulses produced short chain fatty acids (SCFA) after 24 h of in vitro fermentation by human colonic microflora. IF from black bean and lentil were best substrates for the fermentative production of butyric acid. CONCLUSIONS It is concluded that the IF of pulses might be an important source of bioactive compounds.

In vitro digestibility and resistant starch content of some industrialized commercial beans (Phaseolus vulgaris L.)

Commercial bean products were studied in terms of chemical composition and starch digestibility. In general, commercial cooked flours did not show differences in protein and ash contents. Canned beans also did not show statistical differences (α=0.05) in protein, but they were different in ash, perhaps due to botanical variety. Lipid content varied in the different flours, due to the formulation used in their preparation, whereas the canned bean samples had similar lipid values. Canned samples had the highest available starch (AS) values. These results suggest that the drying of samples decreases AS. Canned beans had the lowest total resistant starch (RS) values, and the flours obtained from canned seeds had the highest. These results agree with AS content in the samples. Retrograded resistant starch (RS type 3) showed the same pattern as RS (type 2+type 3), but with lower absolute values. The in vitro α-amylolysis rate for canned beans and commercial flours was lower than for samples dried in the laboratory. Thus, the additional drying step increased the hydrolysis rate of the samples. Therefore, depending on the specific dietetic use of beans, appropriate processing methods and formulations are needed.

Chemical composition, carbohydrate digestibility, and antioxidant capacity of cooked black bean, chickpea, and lentil Mexican varieties Composición química, digestibilidad de carbohidratos, y capacidad antioxidante de variedades mexicanas cocidas de frijol negro, garbanzo, y lenteja

The consumption of legume seeds in developing countries is very important because of their low cost and valuable nutritional characteristics (high protein, digestible and indigestible carbohydrates, and polyphenols content). However, limited information is available on the indigestible carbohydrates and the antioxidant capacity of legumes growing in Mexico. The cooked seeds of three Mexican pulses (black bean, chickpea, and lentil) were evaluated regarding their chemical composition, in vitro starch digestibility, polyphenols content and antioxidant capacity. The highest protein contents were recorded in chickpeas and lentils with no difference between them. Black bean presented the highest dietary fiber, resistant starch, and total indigestible fraction contents. The highest polyphenols and anthocyanins contents were shown by lentil and black bean, respectively. However, black bean exhibited the highest antioxidant capacity, which suggess an important role for anthocyanins in this effect. Present data confirm these legumes as a good source of indigestible carbohydrates and natural antioxidants; their consumption might have a role in preventing diabetes and other chronic-degenerative diseases.

Combining functional features of whole-grain barley and legumes for dietary reduction of cardiometabolic risk: a randomised cross-over intervention in mature women.

The usefulness of dietary strategies against cardiometabolic risk is increasingly being acknowledged. Legumes and whole grains can modulate risk markers associated with cardiometabolic diseases, but their possible additive/synergistic actions are unknown. The objective of the present study was to assess, in healthy subjects, the effect of a diet including specific whole-grain barley products and legumes with prior favourable outcomes on cardiometabolic risk parameters in semi-acute studies. A total of forty-six overweight women (50-72 years, BMI 25-33 kg/m² and normal fasting glycaemia) participated in a randomised cross-over intervention comparing a diet rich in kernel-based barley products, brown beans and chickpeas (D1, diet 1 (functional diet)) with a control diet (D2, diet 2 (control diet)) of similar macronutrient composition but lacking legumes and barley. D1 included 86 g (as eaten)/d brown beans, 82 g/d chickpeas, 58 g/d whole-grain barley kernels and 216 g/d barley kernel bread. Both diets followed the Nordic Nutrition Recommendations, providing similar amounts of dietary fibre (D1: 46·9 g/d; D2: 43·5 g/d), with wheat-based products as the main fibre supplier in D2. Each diet was consumed for 4 weeks under weight-maintenance conditions. Both diets decreased serum total cholesterol, LDL-cholesterol and HDL-cholesterol levels, but D1 had a greater effect on total cholesterol and LDL-cholesterol levels (P< 0·001 and P< 0·05, respectively). D1 also reduced apoB (P< 0·001) and γ-glutamyl transferase (P< 0·05) levels, diastolic blood pressure (P< 0·05) and the Framingham cardiovascular risk estimate (P< 0·05). D1 increased colonic fermentative activity, as judged from the higher (P< 0·001) breath hydrogen levels recorded. In conclusion, a specific barley/legume diet improves cardiometabolic risk-associated biomarkers in a healthy cohort, showing potential preventive value beyond that of a nutritionally well-designed regimen.

PASTA ADDED WITH CHICKPEA FLOUR: CHEMICAL COMPOSITION, IN VITRO STARCH DIGESTIBILITY AND PREDICTED GLYCEMIC INDEX PASTA ADICIONADA CON HARINA DE GARBANZO: COMPOSICIÓN QUÍMICA, DIGESTIBILIDAD IN VITRO DEL ALMIDÓNY PREDICCIÓN DEL ÍNDICE GLUCÉMICO

Abstract Pasta was prepared with of durum wheat flour mixed with chickpea flour at two different levels and its chemical composition, in vitro starch digestibility and predicted glycemic index were assessed. Protein, ash, lipid, and dietary fiber content increased while total starch decreased with the chickpea flour level in the composite pasta, all in accordance to the composition of the legume flour. Potentially available starch decreased and resistant starch (RS) increased by adding chickpea flour to the pasta. The main indigestible starch component in composite spaghetti was the fiber-associated RS, representing up to 50 % of total RS levels. The starch hydrolysis index (HI) decreased as chickpea flour in the pasta increased, reflecting the slow and low digestion of the starch in the leguminous ingredient. Predicted glycemic index was lower in spaghetti added with chickpea flour than in durum wheat-control pasta. Pasta added with chickpea flour might be a dietetic alternative for people with low-calorie requirements. Resumen Se elaboró pasta mezclando sémola de trigo con harina de garbanzo a dos niveles y se evaluó su composición química, digestibilidad del almidón in vitro y se predijo el índice glucémico. El contenido de proteína, ceniza, lípidos y fibra dietética incrementó mientras que el almidón total disminuyó con el contenido de harina de garbanzo en la pasta, esto debido a la composición de la harina de la leguminosa. El contenido de almidón disponible disminuyó y el almidón resistente (AR) incrementó con la adición de la harina de garbanzo a la pasta. El principal componente del almidón no digestible en el espagueti con harina de garbanzo fue el AR asociado a fibra, que representó más del 50 % del AR total. El índice de hidrólisis (IH) del almidón disminuyó con el incrementó del nivel de harina de garbanzo en la pasta, reflejando la baja y lenta digestión del almidón de la leguminosa. La predicción del índice glucémico fue menor en el espagueti adicionado con harina de garbanzo que la muestra control. La pasta adicionada con harina de garbanzo puede ser una alternativa dietética para personas con bajos requerimientos calóricos. Palabras clave: Índice glucémico, composición química, pasta, garbanzo, almidón resistente, fibra dietética

Composite Durum Wheat Flour/Plantain Starch White Salted Noodles: Proximal Composition, Starch Digestibility, and Indigestible Fraction Content

ABSTRACT In search of a way to improve the nutritional profile of noodles, we prepared them with various mixtures of durum wheat flour and isolated plantain starch, and tested their proximal composition. Cooked noodles were assessed for in vitro starch digestibility, indigestible fraction content, and predicted glycemic index. The protein content declined with the addition of plantain starch. Both total starch (TS) level and the content of starch available for digestible enzymes (AS) decreased as the plantain starch level increased, a pattern that may be related to increased starch lixiviation during cooking of noodles containing plantain starch. There was an inverse pattern for resistant starch (RS). RS content in control (durum wheat flour) noodles was ≈50% lower than in the samples containing plantain starch. The soluble indigestible fraction (SIF) content in all samples was higher than the insoluble counterpart (IIF). The total indigestible fraction varied according to the wheat substitution level. Al...