Silvina Rosa Drago

Chemical composition, nutritional and antioxidant properties of the red edible seaweed Porphyra columbina

Abstract Proximate composition, fatty acids and amino acid profiles and nutritional (chemical score, protein digestibility, PDCAAS and mineral dialyzability) and antioxidant properties (TEAC, DPPH and power reduction) from Porphyra columbina were evaluated. Total dietary fiber (48.02 ± 1.13 g/100 g dry weight) and protein (24.61 ± 0.21 g/100 g dry weight) were the two most abundant components in this seaweed. The main saturated and unsaturated fatty acids were C16:0 and C20:5 (n−3), respectively. The limiting amino acid was tryptophan with a chemical score of 57%. Protein digestibility was 74.33 ± 3.0%. Porphyra columbina has high mineral content with good Na/K relationship and medium value of potential mineral accessibility (P, Ca and Zn dializability: 18.75 ± 0.01, 17.62 ± 0.16 and 16.70 ± 0.44, respectively). The highest antioxidant properties were obtained with an acetone/water extraction system. This work provides important information about chemical composition and nutraceutical new properties of P. columbina.

Effects of extrusion conditions on physical and nutritional properties of extruded whole grain red sorghum (sorghum spp)

Abstract In order to analyze the effects of extrusion temperature (T: 164, 182, 200 °C) and grits moisture content (g/100 g sample) (%M: 14, 16.5, 19) on textural and physicochemical properties of red sorghum extrudates, whole grain flour was extruded according to a factorial experimental design. The higher values for specific mechanical energy consumption (1006.98 J/g) and expansion (3.36) were obtained at 164 °C–14%M and for sensorial hardness at 164 °C–19%M. While for specific volume, the highest value (10.41 cm3/g) was obtained at 200 °C–14%M. Water solubility and water absorption were directly related with T and inversely with M. Microscopic observation of the samples indicates that the greatest cooking degree was obtained at 200 °C–4%M and the lowest at 164 °C–19%M. Extrusion at 182 °C–14%M allows obtaining an expanded product with good properties. Proximal composition did not show statistically significant differences with raw sample. Extruded sample showed a 25.4% reduction of available lysine and a 31% increase in protein digestibility.

Soaking and extrusion effects on physicochemical parameters, phytic acid, nutrient content and mineral bio-accessibility of whole rice grain

Abstract A combination of soaking and extrusion processes of whole rice grain was studied. The effects of temperature (35–55 °C) and time (24–48 h) of soaking treatment on phytic acid (PA), protein and ashes losses using a factorial design were evaluated. Taking into account ash, protein and PA losses, whole rice was soaked 24 h at 45 °C and extruded using a Brabender single screw extruder. Effects of extrusion temperature (160–190 °C) and moisture content (14–19 g/100 g) on product characteristics were evaluated using surface response methodology. Values corresponding to the different responses were: Expansion (1.64–3.28), Specific Volume (5.68–11.06 cm3/g), Water absorption (3.41–4.43 mL/g) and Solubility (45.44–66.20 g/100 g). The content of PA was reduced from 740.09 to 163.47 mg/100 g (77%) after both processes, resulting in a higher mineral bio-accessibility, and a 7.3% decrease of protein digestibility. Total soluble phenolics and trolox equivalent antioxidant capacity (TEAC) were affected according to the treatment. Both treatments were important to obtain a nutritionally improved whole grain product.

Food matrix and cooking process affect mineral bioaccessibility of enteral nutrition formulas

BACKGROUND When enteral formulas (EF) are administered orally as a supplement to the normal diet, they are often mixed with conventional foods or included in recipes in order to seek new flavors and textures and avoid monotony. The aims of this work were to study the bioaccessibility of Fe, Zn and Ca from commercial EF and the impact upon their incorporation into sweet preparations. Twenty commercial EF, before and after inclusion in sweet food (rice pudding, RP; banana smoothie, BS; tea, T; chocolate dessert, CD) were evaluated regarding Fe, Zn and Ca dialyzability (%DFe , %DZn , %DCa ) as an estimator of mineral bioaccessibility. RESULTS Fe, Zn and Ca dialyzability from EF was variable and generally low. Heating during EF-sweet food preparation (T and CD) lowered values to 44.1 %DFe , possibly due to degradation of vitamin C, and 52.7 %DZn and 25.3 %DCa , due to the interaction with food components. CONCLUSION EF and EF-sweet foods did not represent a good supply of Fe, Zn and Ca as recommended. This study demonstrated how the bioaccessibility of these minerals is affected by the food matrix in which EF is included as well as heating during food preparation.

Physicochemical properties and structural characteristics of whole grain Oryza sativa L. with different treatments

Physicochemical properties and structural characteristics of whole rice flours with different treatments (soaking, germination and extrusion cooking) were studied. Water solubility, water absorption, crystallinity, adsorption isotherms (BET and GAB models), and glass transition temperature of the samples were determined. Water solubility and water absorption were enhanced by extrusion cooking process (3.17–4.98 vs. 24.1–53.76 g/100 g and 2.77–3.05 vs. 4.46–7.04 ml/g, respectively), but crystallinity was decreased (30–33 vs. 4–16%). Adsorption isotherms showed that extruded samples exhibited higher equilibrium moisture content as compared with their corresponding non-extruded samples (5.0–19.2 vs. 4.0–16.1 g water/g solids). There were no changes in glass transition temperature values in the studied moisture range (3.8–16 g/100 g). These results allow the correct use of whole rice flours with different treatments in foods and also contributed to the knowledge of stabilization of the products.

Germination and extrusion as combined processes for reducing phytates and increasing phenolics content and antioxidant capacity of Oryza sativa L. whole grain flours.

Abstract Whole rice (WR) products with low phytic acid (PA) content and enhanced bio-functional components were obtained by the combination of germination and extrusion processes. Germination conditions (24 h – 35 °C), with a previous soaking process (24 h – 20 °C), were chosen according to the remnant PA content and germination rate. Specific mechanical energy consumption, expansion, sensorial and mechanical hardness, specific volume, solubility, water absorption, free phenolic content (FPC) and antioxidant capacity were evaluated. Results indicated that 175 °C and 14 g 100 g−1 of moisture were the most appropriate conditions to obtain expanded products and precooked flours based on germinated WR. Selected extruded product presented less PA content (821.6 9 ± 10.3 versus 695.2 0 ± 1.6 mg 100 g−1) and higher Fe bio-accessibility, FPC (45.2 9 ± 1.61 versus 66.3 5 ± 3.35 mg GAE g−1) and antioxidant capacity compared with WR (34.9 5 ± 0.8 versus 54.6 3 ± 1.6 µmol trolox g−1). Combining germination–extrusion processes could be a strategy to obtain expanded products or precooked flours based on WR with enhanced health benefits.

Effects of puddings containing whey protein and polydextrose on subjective feelings of appetite and short-term energy intake in healthy adults

Abstract The aim of this study was to investigate the effects of puddings with whey protein (WP) and polidextrose (PX) on appetite feelings and energy intake. A single-blind randomized, crossover study was carried out in 25 healthy adults. Participants consumed two different puddings, including control or test pudding (12.9 g WP and 6 g PX). Two testing days were completed, including satiety questionnaires and ad libitum lunch. For all participants, energy intake at lunch was similar after consumption of control or test pudding. Consumption of test pudding did not favor subjective feelings of appetite during satiation period, but it decreased iAUC for desire to eat by 24.2% (p = .049) and marginally decreased iAUC for hunger (p = .081) by 24.3% as compared with the control during the satiety. These data suggest that the consumption of pudding with WP and PX might be a useful strategy to decrease desire of eat.

Sensory and instrumental textural changes in fillets from Pacú (Piaractus mesopotamicus) fed different diets

The influence of two dietary treatments on quality properties, like textural parameters, sensory profile, and nutritional composition of Pacú fillets (Piaractus mesopotamicus) were studied. Pacú were fed diets based on plant-meals containing 13 g 100 g-1 fish meal (FMD) or bovine plasma protein concentrate (BPPD) as a complete replacement of fish meal. Harvested fish were filleted, kept frozen at -20C for 7 days before analysis. Chemical composition, amino acid and fatty acid profiles, and CIE-Lab parameters of fillets were measured. Sensory characteristics and texture profile analysis (TPA) were conducted for cooked portions. Average values of TPA hardness, chewiness, and deformability modulus were higher in BPPD samples but there was no significant difference in cohesiveness between samples. In accordance with TPA, higher values of firmness and chewiness as well as less flaky muscle were detected in BPPD samples by sensory panel. However, there was no significant difference in the characteristics associated with higher freshness between samples. Total color difference was lower in BPPD samples. Differences in protein, lipid, ash, and moisture content of FMD or BPPD fillets were not found (p > .05). BPPD fillets showed higher basic and sulfur amino acids. Saturated and polyunsaturated fatty acid contents were higher in FMD fillets than BPPD. However, a significantly higher n-6/n-3 ratio for FMD fillets was observed. The higher values of textural parameters observed for BPPD cooked fillets and the lower n-6/n-3 ratio imply a better sensory and nutritional quality of fillets from fish fed with BPPD. PRACTICAL APPLICATIONS: A complete study is presented on how the source of protein and lipids in feed affect both the sensory profile and the nutritional composition of fillets of Pacú (omnivorous temperate freshwater fish) cultivated in the second stage of fattening. Instrumental texture analysis of the fillets is presented, identifying the indicators that match with sensorial analysis. This analysis can help the industry of aquaculture in the evaluation of new ingredients or diets for fish feeding with impact in the quality of fillets.

Effects of cereal bar containing polydextrose on subjective feelings of appetite and energy intake in overweight adults over 15 d

Abstract The effects of 15 d polydextrose (16.7 g) consumption on energy intake (EI) and appetite feelings were investigated. Overweight adults consumed a polydextrose-bar or a control-bar matched in energy content as a midmorning snack for 15 consecutive days in a single-blind, randomised, crossover design. The two 15-d intervention periods were separated by a 15-d washout period. On the day 1 and the day 15 of each intervention period, energy intake (primary outcome) and appetite feelings (secondary outcome) were assessed. There were not significant main effects of the day, type of bar, or their interaction for EI (at lunchtime test meal, at rest of the day, or at total daily) or subjective feelings (hunger, desire to eat, fullness, and prospective food consumption) during the satiation and satiety periods. The results showed the consumption of polydextrose-bar during 15 d did not significantly affect energy intake and subjective feelings of appetite in overweight adults.

Losses of nutrients and anti-nutrients in red and white sorghum cultivars after decorticating in optimised conditions

Abstract The aims were to optimise pearling process of red and white sorghum by assessing the effects of pearling time and grain moisture on endosperm yield and flour ash content and to assess nutrient and anti-nutrient losses produced by pearling different cultivars in optimised conditions. Both variables significantly affected both responses. Losses of ashes (58%), proteins (9.5%), lipids (54.5%), Na (37%), Mg (48.5%) and phenolic compounds (43%) were similar among red and white hybrids. However, losses of P (30% vs. 51%), phytic acid (47% vs. 66%), Fe (22% vs. 55%), Zn (32% vs. 62%), Ca (60% vs. 66%), K (46% vs. 61%) and Cu (51% vs. 71%) were lower for red than white sorghum due to different degree of extraction and distribution of components in the grain. Optimised pearling conditions were extrapolated to other hybrids, indicating these criteria could be applied at industrial level to obtain refined flours with proper quality and good endosperm yields. Graphical Abstract