Synchrotron-based and globar-sourced molecular (micro)spectroscopy contributions to advances in new hulless barley (with structure alteration) research on molecular structure, molecular nutrition, and nutrient delivery

Cereal grain fiber composition modifies phosphorus digestibility in grower pigs

Increased fermentable carbohydrates (e.g., β-glucan, amylose) may increase endogenous losses including for P, and thereby reduce apparent total tract digestibility (ATTD) of P. The present study assessed effects of barley cultivars varying in fermentable starch and fiber on apparent ileal digestibility (AID) and ATTD of P, myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate; InsP6) and Ca, and standardized total tract digestibility (STTD) of P and the presence of lower inositol phosphates (InsP) compared to wheat. In a 6 (period) × 5 (diet) Youden square, 7 ileal-cannulated barrows (initial BW, 27.7 kg) were fed diets containing 80% of 1 of 5 cereal grains differing in amylose, β-glucan, and fiber content: 1) high-fermentable, high-β-glucan, hull-less barley (HFB); 2) high-fermentable, high-amylose, hull-less barley (HFA); 3) moderate-fermentable, hull-less barley (MFB); 4) low-fermentable, hulled barley (LFB); and 5) low-fermentable, hard red spring wheat (LFW). On dry matter (DM) basis, cereal grains contained between 0.32 to 0.53% total P and 0.24 to 0.50% InsP6-P. The InsP6-2-P was calculated as the sum of all detected InsP-P (InsP6-P to InsP2-P) in the sample. The P release of degraded InsP-P was calculated by using the following equation: sum InsP6-2-Pdiet (g/kg DM) × (AID or ATTD sum InsP6-2-P (%) / 100). Data were analyzed using a mixed model with diet as fixed effect, and pig and period as random effects. On DM basis, diets contained 41.4 to 50.6% starch, 0.88 to 8.54% β-glucan, 0.81 to 0.89% total P, and 0.19 to 0.35% InsP6-P. The MFB, LFB, and LFW had greater (P < 0.05) diet AID of P than HFB and HFA, and MFB had greater (P < 0.05) diet ATTD and STTD of P than HFB. The ATTD of InsP6-P was greater (P < 0.05) for HFB than LFB and the ATTD of the sum InsP6-2-P was greater (P < 0.05) for HFB and HFA than LFB. Total tract P release was greater (P < 0.001) for HFB, HFA, and LFW than MFB and LFB. The LFW had greater (P < 0.05) ATTD of Ca than LFB. Diet β-glucan content was not correlated with STTD of P (R 2 = 0.03) or ATTD of InsP6 (R 2 = 0.05). In conclusion, cereal grains high in fermentable fiber, e.g., amylose and β-glucans included in specific hull-less barley cultivars, had lower diet AID, ATTD, and STTD of P, but greater ATTD of InsP6-P and sum InsP6-2-P. Carbohydrate fermentation thus results in greater total tract P release from InsP-P hydrolysis.

Synchrotron-radiation sourced SR-IMS molecular spectroscopy to explore impact of silencing TT8 and HB12 genes in alfalfa leaves on the molecular structure and chemical mapping

Advanced synchrotron-based vibrational molecular spectroscopy (SR-IMS) has been developed to image molecular chemistry in biological tissues within cellular and subcellular dimension. However, it is seldomly used in gene-transformation and gene-silencing study. The objectives of this study were to apply synchrotron-based vibrational molecular spectroscopy (SR-IMS) to determine the molecular structural changes and chemical mapping of alfalfa leaves induced by silencing of TT8 and HB12 genes in alfalfa in comparison with wild type of alfalfa. Five alfalfa leaves from each alfalfa genotype were selected for FTIR spectra collection and chemical mapping with synchrotron-based FTIR microspectroscopy (SR-IMS). Peak heights and areas of empirical regions were analyzed, and peak areas of previous regions were mapped for each sample using OMNIC 7.3. Results showed that transformed alfalfa had higher peak height and area of carbonyl CO (CCO), compared with wild type (WT). Chemical groups maps for carbohydrate, amide and lipid-related regions were successfully obtained. HB12-silenced (HB12i) had higher carbohydrate intensity both in the mesophyll and epidermises, whereas TT8-silenced (TT8i) and WT only had higher carbohydrate spectral peak intensity in epidermises. In addition, HB12i had higher CCO intensity and lower lignin intensity compared with TT8i and WT. All alfalfa genotypes had higher intensity of amide and asymmetric and symmetric CH2 and CH3 (ASCC) area in mesophylls. In conclusion, silencing of HB12 and TT8 genes in alfalfa both increased CCO profiles of alfalfa leaves, while silencing of HB12 had more impacts on chemical localization in alfalfa leaves.

Processing induced changes in physicochemical structure properties and nutrient metabolism and their association in cool-season faba (CSF: Vicia L.), revealed by vibrational FTIR spectroscopy with chemometrics and nutrition modeling techniques

This review aims to update recent progress in processing induced molecular structure changes in the association of physicochemical structure properties with nutritional metabolism in cool-season faba bean (Vicia L.), which was revealed using advanced vibrational molecular spectroscopy in combination with chemometrics and advanced nutrient modeling techniques. The review focused on strategies to improve the utilization of the cool-season faba bean through heat-related technological treatments and the relationship of the processing induced molecular structural changes to nutrient delivery and metabolism in ruminant systems. The updated methods with truly absorption nutrient modeling techniques and advanced vibrational molecular spectroscopy techniques sourced by globar and synchrotron radiation (e.g. NIR, near Infrared, FTIR, Fourier transform infrared, DRIFT, diffuse reflectance infrared Fourier transform, ATR-FTIR, attenuated total reflectance-FTIR, FTIRM, FTIR micro-spectroscopy, SR-FTIRM, synchrotron radiation- FTIRM) to study cool-season faba bean were reviewed. This article provides an insight and a new approach on how to combine advanced nutrient modeling techniques with cutting-edge vibrational molecular spectroscopic techniques to study the processing induced molecular structure change in relation to molecular nutrition of cool-season Vicia faba as well as the interaction between molecular structure and molecular nutrition.

Using advanced vibrational molecular spectroscopy (ATR-Ft/IRS and synchrotron SR-IMS) to study an interaction between protein molecular structure from biodegradation residues and nutritional properties of cool-climate adapted faba bean seeds

The objective of this study was to use advanced vibrational molecular spectroscopy (ATR-Ft/IRS) to study an interaction between legume protein molecular structure from biodegradation residues and nutritional properties of newly developed genotypes of cool-climate adapted faba bean seed with low and normal tannin levels grown in western Canada. Protein molecular structures including amide I, II areas and peak heights, α-helix and β-sheet peak heights in rumen biodegradation residues were determined by using attenuated total reflectance Fourier transform infrared molecular spectroscopy (ATR-FTIR). The nutritional properties were determined which included chemical and nutrient profiles, in situ rumen degradation kinetics, rumen protein degradation, and intestinal protein digestion in the newly developed genotypes of faba bean seeds with low and normal tannin levels. The results showed that the spectral intensity of faba bean varieties with a normal tannin level in rumen biodegradation residues was greater (P < 0.05) than that with a low tannin level. The spectral intensity of amide I, II areas and peak heights, α-helix and β-sheet peak heights in all genotypes (except the variety of Snowdrop) in biodegradation residuals of faba bean seeds had a unique pattern with increasing first and then decreasing with the increasing of rumen incubation time. The molecular structures of protein (α-helix, ratio of α-helix to β-sheet height and amide I to II area, R² > 0.6) were associated with in situ degradation kinetics - soluble (S) and potential degradable fractions (D) and rumen protein degradation- bypass or undegraded protein (BCP or RUP). The molecular spectral parameters in the FTIR fingerprint region didn't form cluster among different genotypes in residual faba bean seeds in 12 h and 24 h incubation, which indicate they had similar protein molecular structures after incubation. In conclusion, there was an interaction between protein molecular structure from biodegradation residues and nutritional properties of newly developed cool-climate adapted faba bean seeds with normal and low level of tannin. The cool-climate adapted genotype had an impact on the protein molecular structure, and the protein utilization and metabolism were predictable from protein spectral molecular structures after rumen biodegradation with ATR-Ft/IRS spectroscopy.

Interactive Curve-Linear Relationship Between Alteration of Carbohydrate Macromolecular Structure Traits in Hulless Barley (Hordeum vulgare L.) Grain and Nutrient Utilization, Biodegradation and Bioavailability

The aim of this study was to reveal an interactive curve-linear relationship between altered carbohydrate macromolecular structure traits of hulless barley cultivars and nutrient utilization, biodegradation, as well as bioavailability. The cultivars had different carbohydrate macromolecular traits, including amylose (A), amylopectin (AP), and β-glucan contents, as well as their ratios (A:AP). The parameters assessed included: (1) chemical and nutrient profiles; (2) protein and carbohydrate sub-fractions partitioned by the Cornell Net Carbohydrate and Protein System (CNCPS); (3) total digestible nutrients (TDN) and energy values; and (4) in situ rumen degradation kinetics of nutrients and truly absorbed nutrient supply. The hulless barley samples were analyzed for starch (ST), crude protein (CP), total soluble crude protein (SCP), etc. The in situ incubation technique was performed to evaluate the degradation kinetics of the nutrients, as well as the effective degradability (ED) and bypass nutrient (B). Results showed that the carbohydrates (g/kg DM) had a cubic relationship (p < 0.05), with the A:AP ratio and β-glucan level; while the starch level presented a quadratic relationship (p < 0.05), with the A:AP ratio and cubic relationship (p < 0.05), with β-glucan level. The CP and SCP contents had a cubic relationship (p < 0.05) with the A:AP ratio and β-glucan level. The altered carbohydrate macromolecular traits were observed to have strongly curve-linear correlations with protein and carbohydrate fractions partitioned by CNCPS. For the in situ protein degradation kinetics, there was a quadratic effect of A:AP ratio on the rumen undegraded protein (RUP, g/kg DM) and a linear effect of β-glucan on the bypass protein (BCP, g/kg DM). The A:AP ratio and β-glucan levels had quadratic effects (p < 0.05) on BCP and EDCP. For ST degradation kinetics, the ST degradation rate (K_d), BST and EDST showed cubic effects (p < 0.05) with A:AP ratio. The β-glucan level showed a cubic effect on EDST (g/kg DM) and a quadratic effect on BST (g/kg ST or g/kg DM) and EDST (g/kg DM). In conclusion, alteration of carbohydrate macromolecular traits in hulless barley significantly impacted nutrient utilization, metabolic characteristics, biodegradation, and bioavailability. Altered carbohydrate macromolecular traits curve-linearly affected the nutrient profiles, protein and carbohydrate fractions, total digestible nutrient, energy values, and in situ degradation kinetics.