Oat starch: Physico-chemical, morphological, rheological characteristics and its applications - A review

Saccharomyces cerevisiae Fermentation of 28 Barley and 12 Oat Cultivars

As barley and oat production have recently increased in Canada, it has become prudent to investigate these cereal crops as potential feedstocks for alcoholic fermentation. Ethanol and other coproduct yields can vary substantially among fermented feedstocks, which currently consist primarily of wheat and corn. In this study, the liquified mash of milled grains from 28 barley (hulled and hull-less) and 12 oat cultivars were fermented with Saccharomyces cerevisiae to determine concentrations of fermentation products (ethanol, isopropanol, acetic acid, lactic acid, succinic acid, α-glycerylphosphorylcholine (α-GPC), and glycerol). On average, the fermentation of barley produced significantly higher amounts of ethanol, isopropanol, acetic acid, succinic acid, α-GPC, and glycerol than that of oats. The best performing barley cultivars were able to produce up to 78.48 g/L (CDC Clear) ethanol and 1.81 g/L α-GPC (CDC Cowboy). Furthermore, the presence of milled hulls did not impact ethanol yield amongst barley cultivars. Due to its superior ethanol yield compared to oats, barley is a suitable feedstock for ethanol production. In addition, the accumulation of α-GPC could add considerable value to the fermentation of these cereal crops.

Structural characterization and physicochemical properties of starch from four aquatic vegetable varieties in China

Nelumbo nucifera Gaertn., Eleocharis dulcis, Sagittaria sagittifolia L., and Trapa bispinosa Roxb. are common aquatic vegetables that are rich in starch. Starches from these four aquatic vegetables and their applications in edible films were studied to facilitate full use of starch resources. Significant differences in transparency, freeze-thaw stability, water solubility index, swelling power, water and oil absorption capacities, starch particle morphology, and rheology were observed among the starches from these four aquatic vegetables. All starches exhibited a typical "A" type diffraction pattern. N. nucifera, E. dulcis, and S. sagittifolia starches have similar thermal properties, while T. bispinosa starch has a higher gelatinization temperature. S. sagittifolia starch film has the highest transparency and lower WVP and water solubility. These results will promote the development of products based on starch obtained from aquatic vegetables.

The contribution of β-glucan and starch fine structure to texture of oat-fortified wheat noodles

Wheat flour noodles are sometimes fortified with β-glucan for nutritional value, but this can decrease eating quality. The contributions of β-glucan and starch molecular fine structure to physicochemical properties of wholemeal oat flour and to the texture of oat-fortified white salted noodles were investigated here. Hardness of oat-fortified noodles was controlled by the longer amylopectin chains (DP ≥ 26) and amount of longer amylose chains (DP ≥ 1000). Higher levels of β-glucan, in the range from 3.1 to 5.2%, result in increased noodle hardness. Pasting viscosities of wholemeal oat flour positively correlate with the hardness of oat-fortified noodles. The swelling power of oat flour is not correlated with either pasting viscosities of oat flour or noodle hardness. Longer amylopectin chains and the amount of longer amylose chains both control the pasting viscosities of oat flour, which in turn affect noodle texture. This provides new means, based on starch and β-glucan molecular structure, to choose oats with optimal starch structure and β-glucan content for targeted oat-fortified noodle quality.