Studies on Brassica carinata Seed. 2. Carbohydrate Molecular Structure in Relation to Carbohydrate Chemical Profile, Energy Values, and Biodegradation Characteristics

Abstract

The objectives of this study were to investigate (1) the carbohydrate chemical profile, (2) the energy values, (3) the rumen neutral detergent fiber (NDF) degradation kinetics, (4) the carbohydrate-related functional group structural features using a Fourier transform infrared (FTIR) spectroscopic technique with attenuated total reflectance (ATR), and (5) the correlations between carbohydrate intrinsic structural features and nutritional profiles in three strains of Brassica carinata in yellow and brown seed coats, with comparison to canola seed as a reference. The results showed that yellow B. carinata strains 111000EM and AAC A100 were lower for contents of neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and carbohydrate (CHO) and higher for contents of total digestible nutrients (TDN), energy values, and effective degradable NDF (EDNDF) than brown-seeded 110915EM. In comparison, brown canola seed (Brassica napus L.) had more fiber content and less EDNDF. Also, carinata strains showed significantly different IR intensities in structural carbohydrate (SCHO), cellulosic compounds (CELC), and total CHO profiles. These structural variations might be one of the possible reasons for various fiber profile and biodegradation characteristics for ruminants in oilseeds. However, multivariate analyses within carbohydrate regions indicated there were still some structural relationships among the four oilseed samples. Moreover, the correlation study showed that the changes of CELC and CHO peak intensities were highly related with some changes in CHO chemical profile, energy values, and in situ NDF degradation kinetics in B. carinata and canola seeds. Further study with a large sample size is still necessary to figure out whether CHO molecular spectral information could be used to predict nutrient values and biological behavior in oilseeds.

Univariate and multi‐variate comparisons of protein and carbohydrate molecular structural conformations and their associations with nutritive factors in typical by‐products

“…Most strong correlations within the carbohydrate region were observed between CELC area and tdCP, tdNDF, TDN 3x , ME, and NE m with r = 0.67–0.85 and between TSCHO area with tdCP, TDN 1x , ME 3x and ME with r = 0.71–0.75. Our results were not fully in agreement with those found in previous works targeting Brassica carinata seed, oilseed meals and DDGS . The limited sample sizes ( n = 4–9) or relatively narrow variations existed in both spectroscopic and nutrient information in these studies might account for the inconsistent data.…”

“…Therefore, variation tendencies on peak height and area ratios were found to be various among the by‐product types with the exception of height ratios of SCHO peak 1:2, SCHO peak 1:CELC and area ratio of SCHO:CELC and TCHO:TSCHO which had no changes ( P > 0.05). These results demonstrated that the characteristics of inherent molecular structural makeup in the selected by‐products were not stable, which was in full agreement with previous studies targeting crop residues and Brassica carinata seeds …”

“…Numerous workers reported the close relationships between molecular structural features of protein or carbohydrate related functional groups and nutrient parameters in food/feed samples, such as barley, DDGS, and oilseed or oilseed meals . However, each of these works only focused on limited sample varieties and all the results failed to reach a consistent conclusion.…”

“…The spectral parameters, including peak height and area, were identified with the aid of OMNIC 7.2 software (Thermo Fisher Scientific, Waltham, MA, USA) which is considered as a necessary tool and has been successfully used in previous literature . Within the region (baseline ca .…”

“…Therefore, data obtained only from traditional chemical analysis seems not to be enough for fully effective utilisation of each feed ingredient to animals. This is because we have a better understanding of intrinsic molecular structures of biopolymers, which are usually destroyed during strong chemical reactions, has been the subject of greater focus by animal nutritionists recently . As is well documented, internal structural effects may have a significant role in the variations on the biodegradation behaviour, nutrient quality and availability to animals among the feedstuffs containing the same content of some components, such as protein.…”