Granular Cold Water Gelling Starch Prepared from Chickpea Starch Using Liquid Ammonia and Ethanol

Granular cold water gelling (GCWG) starch was obtained by treatment of native chickpea starch with liquid ammonia at low temperature and atmospheric pressure. A free‐flowing powder of the gelatinized starch granules was produced by adding ethanol to the mixture of starch and liquid ammonia. Four ratios of liquid ammonia to starch (A/S) (2:1, 4:1, 6:1 and 8:1) and four ratios of starch ethanol (S/E) (1:1, 1:2, 1:3 and 1:4) were tested for production of GCWG starch. Homogenous mixtures of liquid ammonia and starch granules appeared when the A/S ratio was >4:1. Treating starch with a 4:1:3 ammonia‐starch‐ethanol (A/S/E) ratio on a w/w/v basis resulted in a free‐flowing powder of gelatinized starch, that formed a gel on addition of water at 23°C. Differential scanning calorimetry (DSC) thermograms of the GCWG starch, regardless of A/S/E ratio, displayed enthalpy values of 2.2–3.1 J/g compared with 15.5 J/g for native starch, indicating disappearance of crystallinity due to modification.     

Environmental Influences on Flour Composition,Dough Rheology,and Baking Quality of Spring Wheat

The highly variable environmental conditions across the Pacific Northwest (PNW) influence the milling and baking quality of wheat grain produced in this region. This study was conducted to compare the flour composition, dough rheology, and baking quality of soft and hard spring wheat grain produced in diverse environments. Thirteen soft and five hard spring wheat cultivars were grown at Lind, WA (semiarid) and Fairfield, WA (high precipitation) for three years. Grain was evaluated for flour composition, rheology, and experimental baked product quality. Flour composition, rheological properties, and baking qualities were primarily influenced by the environment. Protein contents, microSDS values, and water absorption levels were significantly (P < 0.0001) higher for all cultivars grown at Lind compared with those from Fairfield. Cookie diameters were larger (P < 0.0001) for soft flours from Fairfield, whereas loaf volumes were higher (P < 0.0001) for hard wheat flours from Lind. Results indicate that producing soft or hard wheat outside of its optimal climatic zone reduces experimental baked product quality.     

Structure and Functionality of Barley Starches

Amylose contents of prime starches from nonwaxy and high-amylose barley, determined by colorimetric method, were 24.6 and 48.7%, respectively, whereas waxy starch contained only a trace (0.04%) of amylose. There was little difference in isoamylase-debranched amylopectin between nonwaxy and high-amylose barley, whereas amylopectin from waxy barley had a significantly higher percentage of fraction with degree of polymerization < 15 (45%). The X-ray diffraction pattern of waxy starch differed from nonwaxy and high-amylose starches. Waxy starch had sharper peaks at 0.58, 0.51, 0.49, and 0.38 nm than nonwaxy and high-amylose starches. The d-spacing at 0.44 nm, characterizing the amylose-lipids complex, was most evident for high-amylose starch and was not observed in waxy starch. Differential scanning calorimetry (DSC) thermograms of prime starch from nonwaxy and high-amylose barley exhibited two prominent transition peaks: the first was >60°C and corresponded to starch gelatinization; the second was >100°C and corresponded to the amylose-lipid complex. Starch from waxy barley had only one endothermic gelatinization peak of amylopectin with an enthalpy value of 16.0 J/g. The retrogradation of gelatinized starch of three types of barley stored at 4°C showed that amylopectin recrystallization rates of nonwaxy and high-amylose barley were comparable when recrystallization enthalpy was calculated based on the percentage of amylopectin. No amylopectin recrystallization peak was observed in waxy barley. Storage time had a strong influence on recrystallization of amylopectin. The enthalpy value for nonwaxy barley increased from 1.93 J/g after 24 hr of storage to 3.74 J/g after 120 hr. When gel was rescanned every 24 hr, a significant decrease in enthalpy was recorded. A highly statistically significant correlation (r = 0.991) between DSC values of retrograded starch of nonwaxy barley and gel hardness was obtained. The correlation between starch enthalpy value and gel hardness of starch concentrate indicates that gel texture is due mainly to its starch structure and functionality. The relationship between the properties of starch and starch concentrate may favor the application of barley starch concentrate without the necessity of using the wet fractionation process.     

The importance of the gravel excavation industry for the conservation of grassland butterflies

Conservation biology often relies on the protection of (semi)natural habitat remnants. However, the ever increasing human population is taking over natural resources and habitats. Here, contrary to most other studies, we ask how human-associated severe changes in the environment can be used to enrich local biodiversity. We tested if industrial activity (gravel excavation) leads to the creation of habitats that support grassland butterflies and how these areas add to the richness of local species when compared to typical semi-natural habitats (grasslands). We also identified key factors affecting the richness, abundance, diversity and commonness of butterfly species to provide practical recommendations. Species richness, diversity index and the occurrence of rare species were higher in gravel-pit shores than in grasslands. The richness of butterfly species and their abundance were positively affected by the richness of plant species, shrub density and age of the gravel-pit but negatively by the cover of water reservoirs in the surrounding area and the isolation of gravel-pits from grasslands. Butterfly diversity was positively influenced by the richness of plant species and proximity of human settlement but negatively by area of the shore and isolation. Our study is the first one to show the high value of gravel-pits for the conservation of butterflies. We recommend the inclusion of gravel-pits in a system of ecological networks and management of their surroundings to improve the colonization rate of rare species. We suggests that directing interest to the possible positive effects of industrial development on biodiversity may support conservation efforts.     

Thermal Behavior of Whey Protein Concentrate Treated by Heat and High Hydrostatic Pressure and Its Functionality in Wheat Dough

Solutions of commercial whey protein concentrate (CWPC, 82% protein) at 5, 10, 20, and 30% were treated with heat at 90°C or with high hydrostatic pressure (HHP) at 85 Kpsi (Kpsi = 6.9 MPa) for 30 min. A CWPC solution at 20% also was treated for 30 min with heat at 60, 70, 80, and 90°C and HHP at 20, 40, 60, and 85 Kpsi. Differential scanning calorimetry (DSC) thermograms of untreated CWPC (82% protein) showed two endothermic peaks: the first had an enthalpy value of 4.72 J/g between 57 and 86°C, and the second had an enthalpy value of 2.36 J/g between 120 and 143°C. The first enthalpy peak disappeared after heat treatment at 90°C for 30 min and HHP treatment at 85 Kpsi for 30 min, whereas the second peak remained, independent of concentration. The results indicate that HHP treatment caused changes in the protein of CWPC, and the changes were comparable to those caused by high-temperature treatment. Differential scanning calorimetric analysis of CWPC, heat treated at 60°C, showed an enthalpy value for the first peak of 3.34 J/g, ≈1.41 J/g lower than for untreated CWPC. A sharp decrease in enthalpy to 0.52 J/g for the first peak was observed at 70°C, with complete disappearance at 80°C. The second enthalpy peak was present at all temperatures studied, with significantly higher enthalpy values at 90°C than at lower temperatures. DSC value for the first enthalpy peak for CWPC decreased significantly as HHP treatment level increased from 20 to 85 Kpsi. CWPC treated with HHP at 20 Kpsi had an enthalpy value for the first peak that was ≈2 J/g higher than for the untreated sample. It can be postulated that low HHP treatment of 20% of CWPC solution for 30 min promotes the formation of covalent or noncovalent cross-links and strong protein-protein interactions, hence the higher enthalpy values. Scanning electron micrographs showed that spray-dried, untreated CWPC was a globular form, whereas heat- and HHP-treated CWPC was a solid glasslike, porous or spongy form. Incorporation of 10% untreated CWPC into wheat flours decreased mixograph water absorption, extended mixing time, and caused rapid breakdown of gluten after optimum dough development. Incorporation of 10% heat- or HHP-treated CWPC significantly increased mixograph water absorption and extended mixing time compared to the control but decreased mixing time compared to dough fortified by untreated CWPC. Mixing tolerance of dough was restored by both heat- and HHP-treated CWPC.     

Whey Protein Concentrate Treated with Heat or High Hydrostatic Pressure in Wheat-Based Products

Commercial whey protein concentrate (CWPC) treated with heat or with high hydrostatic pressure (HHP) was incorporated by replacement into wheat flour, and its effects on dough rheology and the quality of cookies, noodles, and bread were evaluated. Wheat flour fortified with heat- or HHP-treated CWPC produced smaller cookies than those fortified with untreated CWPC. Increasing the fortification level of heat- or HHP-treated CWPC from 5 to 10% further decreased cookie diameter. The water absorption for noodle dough decreased by 5% with 10% fortification of untreated CWPC. Both heat- and HHP-treated CWPC increased water absorption from 33% in the control to 35.8%. Incorporation of untreated CWPC decreased the lightness (L*) value of Cantonese noodle dough, while dough fortified with heat- or HHP-treated CWPC had higher L* values compared to those of the control. Yellowness (b*) was improved with incorporation of both untreated and treated CWPC. Cooking loss of Cantonese noodles fortified with untreated or heat- or HHP-treated CWPC was comparable to or lower than that of the control. Incorporation of untreated CWPC increased hardness and cohesiveness of Cantonese noodles. Noodles fortified with heat- or HHP-treated CWPC had similar hardness and were softer than the control and the noodles fortified with untreated CWPC. Wheat flour fortified with 10% untreated CWPC produced wet and sticky bread dough and a small loaf (730 mL). Handling properties of dough were improved and bread volume was increased by 50 mL when heat- or HHP-treated CWPC was incorporated. Incorporation of 10% CWPC increased protein content of bread up to 20.2% and also increased the proportion of essential amino acids.     

Comparison of Polyphenol Oxidase Activities in Wheats and Flours from Australian and U.S. Cultivars

Polyphenol oxidase (PPO) activities of wheats from various classes and cultivars (grown both in the U.S.A. and in Australia), of some U.S. and Australian wheats, of wheat flours at various extraction rates and of kernels separated by size from various cultivars were measured by the oxygen electrode method. PPO activity of wheats was affected by both cultivar and growing location. Wheat flour contained on the average 3% of the PPO of the wheat grain. PPO activities of the flours increased as the flour extraction rates increased. Contrary to expectation, for a single cultivar, small kernels contained less PPO (on a weight basis and especially on a kernel basis) than did large kernels. Differences among kernels of various sizes for a single cultivar were smaller than differences in PPO among kernels of comparable sizes among various cultivars.