A comparison of methods to quantify prolamin contents in cereals

Hydrophobic prolamins are endosperm storage proteins accounting for about 40% of the total protein in most cereals seeds. Despite the absence of a reference method, several procedures have been periodically published to quantify prolamins in cereals. The aim of this study was to compare a conventional fractionation assay (LND) vs three other methods: one based on sequential extractions (HAM) and two rapid turbidimetric procedures (L&H and DRO). Prolamins were extracted in duplicate on barley, corn and wheat samples. For the turbidimetric prolamin evaluation in barley and wheat, a universally available purified gliadin, as alternative to purified zein, was also tested as standard reference material (SRM). The extraction prolamin values were different among grain types (P0.05). LND agreed sufficiently well both with HAM and with L&H methods (R2=0.664 and R2=0.703, respectively, P0.05), whereas a higher prolamin quantification was obtained using HAM (P<0.05). Overall, DRO did not provide similar comparison and performance parameters with respect to other method comparisons. The effect of changing purified zein with purified gliadin was noteworthy only for L&H, both for wheat and barley samples (P<0.01). Considering the increasing attention of animal nutritionists on prolamins, our results could get useful information for routine laboratories analysis

Fortification of Durum Wheat Fresh Pasta with Maqui (Aristotelia chilensis) and Its Effects on Technological, Nutritional, Sensory Properties, and Predicted Glycemic Index

Pasta, a staple food worldwide consumed, was fortified with maqui (Aristotelia chilensis) berry powder (MBP) and the effect of MBP inclusion was evaluated concerning technological, nutritional, and sensory properties. Fresh pasta samples were formulated by replacing 0, 7.5, and 15 g 100 g− 1 of durum wheat semolina with MBP. The inclusion of MBP did not affect the moisture content, but the water activity decreased in the fortified samples, while pH values decreased with increasing MBP levels in the recipe. The pasta fully cooking time and the swelling index were reduced, while the cooking loss and the firmness increased with increasing MBP levels. In addition, MBP increased the total dietary fiber, ash, and phenol contents, along with the in vitro antioxidant activities. The starch hydrolysis index and the predicted glycemic index of cooked fresh pasta decreased along with the increase of MBP addition. The MPB addition to fresh pasta could represent a valuable strategy for increasing its nutritional value, maintaining pasta’s technological properties without affecting the sensory acceptability

The Potential of Wine Lees as a Fat Substitute for Muffin Formulations

The current study evaluates the prospect of wine lees (WL), a costless by-product from Amarone winemaking, as a fat replacer in muffin formulation. WL have elsewhere replaced sunflower oil, allowing the creation of 0, 25, 50, 75, and 100% fat-substituted muffins named ML0, ML25, ML50, ML75, and ML100, respectively. Batter rheology, in addition to the textural and colorimetric characteristics, the pore dimension, and the sensory aspect of the different formulations were evaluated. The batter consistency (K) of fat-replaced muffins was lower than that of the control, while the hardness and chewiness of the end products were higher. ML25 and ML50 samples reached the highest volume, while the baking loss decreased due to WL's fiber components. ML25, ML50, ML75, and ML100 accounted for caloric reductions of 9, 18, 22, and 26%, respectively, compared to full-fat muffins. Muffins with WL showed a darker crust and crumb as lightness (L*) decreased. Moreover, a* parameter increased with the increment of WL in the formulation, leading to a redder and less yellow-hued fat-replaced muffin. In conclusion, WL could effectively replace fat in the 25-50% range in muffins, achieving a final product with reduced calories, a higher dietary fiber content, higher volume, and promising sensory aspects

Short communication: In vitro rumen gas production and starch degradation of starch-based feeds depend on mean particle size

Our objective was to model the effect of mean particle size (mPS) on in vitro rumen starch degradation (IVSD) and the kinetics of gas production for different starch-based feeds. For each feed, 2 batches of the same grains were separately processed through 2 different mills (cutter or rotor speed mills), with or without different screens to achieve a wide range of mPS (0.32 to 3.31 mm for corn meals; 0.19 to 2.81 mm for barley meals; 0.16 to 2.13 mm for wheat meals; 0.28 to 2.32 mm for oat meals; 0.21 to 2.36 mm for rye meals; 0.40 to 1.79 for sorghum meals; 0.26 to 4.71 mm for pea meals; and 0.25 to 4.53 mm for faba meals). The IVSD data and gas production kinetics, obtained by fitting to a single-pool exponential model, were analyzed using a completely randomized design, in which the main tested effect was mPS (n = 6 for all tested meals, except n = 7 for corn meals and n = 5 for sorghum meals). Rumen inocula were collected from 2 fistulated Holstein dairy cows that were fed a total mixed ration consisting of 16.2% crude protein, 28.5% starch, and 35.0% neutral detergent fiber on a dry matter basis. The IVSD, evaluated after 7 h of rumen incubation, decreased linearly with increasing mPS for corn, barley, wheat, rye, pea, and faba meals, and decreased quadratically with increasing mPS for the other meals. The y-axis intercept for 7-h IVSD was below 90% starch for corn, barley, and rye feeds and greater than 90% for the other tested feeds. The mPS adjustment factors for the rate of rumen starch degradation varied widely among the different tested feeds. We found a linear decrease in starch degradation with increasing mPS for barley, wheat, rye, and pea meals, whereas we noted a quadratic decrease in starch degradation for the other tested meals. Further, we observed a linear decrease in the rate of gas production with increasing mPS in each tested feed, except for pea meal, which had a quadratic relationship. For each 1 mm increase in mPS, the gas production was adjusted by -0.009 h-1 for corn, -0.011 h-1 for barley, -0.008 h-1 for wheat, and -0.006 h-1 for faba, whereas numerically greater adjustments were needed for oat (-0.022 h-1), rye (-0.017 h-1), and sorghum (-0.014 h-1). These mPS adjustment factors could be used to modify the starch-based feed energy values as a function of mean particle size, although in vivo validation is required

Short communication: The effect of an exogenous enzyme with amylolytic activity on gas production and in vitro rumen starch degradability of small and large particles of corn or barley meals

The objective of this study was to evaluate the effect of exogenous amylase supplementation on gas production and on in vitro rumen starch degradability (IVSD) of different sized particles of corn and barley meals (Cm and Bm, respectively). An aqueous liquid amylase formulation from Bacillus licheniformis was tested at 3 enzyme doses (EnzD; 0, 300 and 1,500 kilo novo units/kg of dry matter) on small (<750 µm) and large (≥750 µm) particle size (PS) of Cm and Bm. Data were analyzed according to a randomized complete block design with a factorial arrangement of treatments; the main tested effects were PS, EnzD, and their interaction. Fermentation run entered in the model as random effect. The mixed rumen fluid was collected from 2 rumen-fistulated Holstein dry dairy cows fed at maintenance (forage:concentrate ratio of 80:20; 12% crude protein; 55% amylase-treated neutral detergent fiber). Small particles of both Cm and Bm had a greater rate of fermentation and shorter lag time than large particles. The rate of starch degradation was greater for small than for large particles of Bm, being 0.187 and 0.125 1/h, respectively. Conversely, the rate of starch degradation of Cm averaged 0.063 1/h and was similar among treatments. Enzyme supplementation tended to reduce lag time and to increase rate of fermentation for both PS of Cm and Bm, with a more pronounced effect for small PS. A limited EnzD effect was measured for IVSD data and rate of starch degradation; PS influenced fermentation parameters and the magnitude of starch degradation more than EnzD. Supplementation with exogenous amylase influenced the rumen fermentation pattern of small and large PS of Cm and Bm, even if the effect of the enzyme supplementation differed according to the PS of cereal meals

Response on Yield and Nutritive Value of Two Commercial Maize Hybrids as a Consequence of a Water Irrigation Reduction

The present study investigated in a practical farm condition the response of two commercial maize hybrids (maturity class FAO rating 700) grown for silage production on chemical composition and digestibility of whole maize plant as consequence of a severe water irrigation reduction. Based on different irrigation applications, water restricted (WR) and fully irrigated (FI) plots received 50 and 200 mm of irrigation water, respectively. A split-plot factorial arrangement in a randomised complete block design with two main plots (WR and FI) and two sub-plots (hybrid A and B) with 12 replications/ treatment was performed. Studied parameters were dry matter (DM) yield, harvest index (HI), chemical composition, rumen in situ DM and neutral detergent fibre disappearance (DMD and NDFD, respectively), indigestible NDF (iNDF), 7h in vitro starch degradability (7hIVSD) and net energy (NE) for lactation content. Total DM and grain yields, HI and chemical composition differed (P<0.05) between FI and WR crops and only slight differences were recorded between hybrids. When compared to FI plants, WR had lower starch and higher fibre contents (P<0.05). Higher DMD (59.2 vs 56.4% DM) and NDFD (61.0 vs 58.4% NDFOM) were measured for FI with respect to WR crops, whereas iNDF was about 36% higher (P<0.05) in WR than FI. Lastly, WR plants had a lower NE content than FI plants (P<0.05). Our research showed that a drastic reduction in water irrigation negatively affected whole plant yield, chemical composition and nutrient availability of forage maize

Effect of Moringa oleifera L. Leaf Powder Addition on the Phenolic Bioaccessibility and on In Vitro Starch Digestibility of Durum Wheat Fresh Pasta

Fresh pasta was formulated by replacing wheat semolina with 0, 5, 10, and 15 g/100 g (w/w) of Moringa oleifera L. leaf powder (MOLP). The samples (i.e., M0, M5, M10, and M15 as a function of the substitution level) were cooked by boiling. The changes in the phenolic bioaccessibility and the in vitro starch digestibility were considered. On the cooked-to-optimum samples, by means of ultra-high-performance liquid chromatography-quadrupole time-of-flight (UHPLC-QTOF) mass spectrometry, 152 polyphenols were putatively annotated with the greatest content recorded for M15 pasta, being 2.19 mg/g dry matter (p &lt; 0.05). Multivariate statistics showed that stigmastanol ferulate (VIP score = 1.22) followed by isomeric forms of kaempferol (VIP scores = 1.19) and other phenolic acids (i.e., schottenol/sitosterol ferulate and 24-methylcholestanol ferulate) were the most affected compounds through the in vitro static digestion process. The inclusion of different levels of MOLP in the recipe increased the slowly digestible starch fractions and decreased the rapidly digestible starch fractions and the starch hydrolysis index of the cooked-to-optimum samples. The present results showed that MOLP could be considered a promising ingredient in fresh pasta formulation

Breadstick fortification with red grape pomace: effect on nutritional, technological and sensory properties

BACKGROUND: Grape pomace (GP), a wine-making by-product rich in dietary fiber (DF) and total phenolic compounds (TPC), is a potential functional ingredient in the fortification of baked goods. RESULTS: In the present study, fortified breadsticks samples were obtained by replacing wheat flour with 0, 5 and 10 g 100 g−1 of powdered GP (GPP). The GPP inclusion affected the rheological properties of the doughs by increasing the water absorption and tenacity (P) at the same time as reducing the extensibility (L), with a significant increase in the P/L value and a decrease in the swelling index (G) value and deformation energy (W). Textural characteristics of breadsticks were influenced by the GPP addition, showing a reduction in hardness and fracturability as the amount of GPP increased in the recipe. The GPP fortified breadsticks exhibited decreased pH, volume and specific volume values compared to the control. The TPC and the antioxidant capacity increased in GPP fortified breadsticks, whereas the increased amount of DF allowed the products to benefit from the claim ‘high fiber content’ at the highest level of GPP inclusion. The sensory evaluation revealed that GPP addition increased wine odor, acidity, bitterness, astringency and hardness, and decreased the regularity of alveolation and friability. Finally, the GPP fortified products achieved good sensorial acceptability. CONCLUSION: GPP improved the nutritional values of fortified breadsticks and changed the rheology of dough and breadsticks' technological properties without affecting sensory acceptability

Effect of Moringa oleifera L. Leaf Powder Addition on the Phenolic Bioaccessibility and on In Vitro Starch Digestibility of Durum Wheat Fresh Pasta

Fresh pasta was formulated by replacing wheat semolina with 0, 5, 10, and 15 g/100 g (w/w) of Moringa oleifera L. leaf powder (MOLP). The samples (i.e., M0, M5, M10, and M15 as a function of the substitution level) were cooked by boiling. The changes in the phenolic bioaccessibility and the in vitro starch digestibility were considered. On the cooked-to-optimum samples, by means of ultra-high-performance liquid chromatography-quadrupole time-of-flight (UHPLC-QTOF) mass spectrometry, 152 polyphenols were putatively annotated with the greatest content recorded for M15 pasta, being 2.19 mg/g dry matter (p &lt; 0.05). Multivariate statistics showed that stigmastanol ferulate (VIP score = 1.22) followed by isomeric forms of kaempferol (VIP scores = 1.19) and other phenolic acids (i.e., schottenol/sitosterol ferulate and 24-methylcholestanol ferulate) were the most affected compounds through the in vitro static digestion process. The inclusion of different levels of MOLP in the recipe increased the slowly digestible starch fractions and decreased the rapidly digestible starch fractions and the starch hydrolysis index of the cooked-to-optimum samples. The present results showed that MOLP could be considered a promising ingredient in fresh pasta formulation

Distilled grape pomace as a functional ingredient in vegan muffins: effect on physicochemical, nutritional, rheological and sensory aspects

Wheat-based vegan muffins were formulated with increasing levels (0, 5 and 10 g per 100 g substitutes to flour) of dried grape pomace powder obtained after distillation (DGPP). The DGPP-muffins showed a greater (P &lt; 0.05) total dietary fibre and a lower (P &lt; 0.05) total starch content to the control. The inclusion of DGPP influenced (P &lt; 0.05) both the batter's rheological properties and the baked muffins' technological characteristics, including the baking loss, the volume, the firmness, the spread ratio and the colour. The in vitro antioxidant activity and the phenolic content increased (P &lt; 0.05) following DGPP inclusion. The untargeted phenolic profiling by UHPLC-HRMS revealed an (P &lt; 0.05) increase of several phenolic classes (i.e. free and bound fractions) following the inclusion of DGPP in the recipe. Flavonoids, mainly anthocyanins, were the most abundant compounds. A quantitative descriptive sensory analysis detected the DGPP-vegan muffins showed good sensory acceptability. The vegan muffin with 5 g per 100 g of DGPP obtained the highest overall acceptability score by the panellists