Warming weather changes the chemical composition of oat hulls

Abstract

The current threats of climate change are driving attention away from the petrochemical industry towards more sustainable and bio‐based production processes for fuels and speciality chemicals. These processes require suitable low‐cost starting material. One potential material assessed here is the oat hull. Its overall chemical composition has so far not been fully characterized. Furthermore, it is not known how it is affected by extreme weather events. Oat hulls (Kerstin and Galant varieties) grown during ‘normal’ weather years (2016 and 2017) are compared to the harvest of the warmer and drier year (2018). Standard methods for determination of plant chemical composition, with focus on carbohydrate composition, are utilized. Oat hulls grown in ‘normal’ weather conditions (2017) are rich in lignocellulose (84%), consisting of 35% hemicellulose, 25% lignin and 23% cellulose. Arabinoxylan was found to be the major biopolymer (32%). However, this composition is greatly influenced by weather variations during the oat growth phase. A lignocellulose reduction of 25% was recorded in the warmer and drier 2018 harvest. Additionally, a 6.6‐fold increase in starch content, a four‐fold increase in protein content and a 60% decrease in phenolic content was noted. Due to its high lignocellulose composition, with an exceptionally large hemicellulose fraction, the chemical composition of oat hulls is unique among agricultural by‐products. However, this characteristic is significantly reduced when grown in warmer and drier weather, which could compromise its suitability for use in a successful biorefinery.

Effect of beak trimming at hatch and the inclusion of oat hulls in the diet on growth performance, feed preference, exploratory pecking behavior, and gastrointestinal tract traits of brown-egg pullets from hatch to 15 weeks of age

“…The physicochemical characteristics of OH, a byproduct of the food industry, vary widely with type of seed, weather conditions, and dehulling process. Schmitz et al (2020) reported that the starch and insoluble fiber (cellulose, hemicellulose, and lignin) contents of OH varied from 2.5 to 16.3% and from 62.6 to 83.9%, respectively.…”

PSII Activity Was Inhibited at Flowering Stage with Developing Black Bracts of Oat

“…It has become increasingly more attractive in recent years due to the discovery of its many health benefits such as lowering cholesterol and reducing glycemic response [ 37 ]. In 2017, the global output of oats attained 26 million tons, and this is expected to increase further in the future [ 38 ]. Bract color is one of the most important characters in variety identification, and yellow bracts are commonly seen in oat cultivars, such as ‘Triple Crown’ and ‘Qingyin No 1’, while black bracts are found in other cultivars, including ‘Qinghai 444’ and ‘Qingyan No 1’ [ 39 , 40 ].…”

Effect of additional water supply during grain filling on protein composition and epitope characteristics of winter oats

“…While the alteration of macroscopic factors such as grain yield, plant height and lodging severity influenced by growing conditions of oats is well demonstrated by the above-cited studies, our knowledge of the effects of growing conditions on the chemical composition as well as on nutritive and functional properties of oat grain is rather limited. The chemical composition of the oat hull is greatly influenced by weather variations during the oat growth phase ( Schmitz et al, 2020 ), but no similar data is available on composition changes in the whole grain. Here, we examined the stability of protein composition properties of winter oats in relation to the excess water available during the grain-filling period.…”