Understanding the differences in molecular conformation of carbohydrate and protein in endosperm tissues of grains with different biodegradation kinetics using advanced synchrotron technology

Using vibrational ATR-FTIR spectroscopy with chemometrics to reveal faba CHO molecular spectral profile and CHO nutritional features in ruminant systems

The non-invasive spectroscopic technique is capable to detect the biomolecular structure spectral features that are associated with biological, nutritional and biodegradation functions. However, to date, no research has been reported on alteration of bioactive compounds/carbohydrate traits on physiochemical and structure spectral characteristics in faba pulse seeds. The objective of this study was to use non-invasive ATR-FTIR spectroscopy with uni- and multivariate analyses to reveal faba [VLF: VLF-1 = CDC snowdrop with low tannin and VLF-2 = FB9-4 with high tannin] CHO molecular spectral profile and CHO nutritional features in ruminant systems. The carbohydrates related major molecular spectral bands included: STCHO (structural carbohydrates, peaks area region and baseline: ca. 1482-1185 cm^-1), CELC (cellulosic compounds, peak area centered at ca. 1238 cm^-1 with region and baseline 1272-1185 cm^-1), TCHO (total carbohydrates, peaks area region and baseline: ca. 1186-939 cm^-1) with three peaks in the region centered at ca. 1147, 1075 and 1012 cm^-1, respectively. The results showed that the high tannin VLF variety VLF-2 had the higher (P < 0.05) peak heights for both STCHO second and third peaks as well as the area of entire STCHO region than low tannin variety VLF-1. Similarly the peak height and area of cellulosic compounds were also higher (P < 0.05) in VLF-2 than VLF-1. Regarding the total carbohydrates spectral profiles, the height and area of all three peaks along with area of entire TCHO region were higher (P < 0.05) in VLF-2 than VLF-1 except the area of TCHO first peak. The multivariate molecular spectral analyses were also able to distinguish between VLF-1 and VLF-2 spectra almost in all respective region. The results of this study indicated that carbohydrates molecular nutrition and structure profiles differed between VLF varieties. This study showed that the alteration of internal traits by modern breeding technology impact molecular nutrition and molecular structure. Vibrational ATR-FTIR spectroscopy could be used as a potential rapid tool to evaluate impact of alternation of carbohydrate on interactive relationship between the molecular structures and nutrient supply and metabolism of carbohydrates in ruminant systems.

A Review of Mid-Infrared and Near-Infrared Imaging: Principles, Concepts and Applications in Plant Tissue Analysis

Plant cells, tissues and organs are composed of various biomolecules arranged as structurally diverse units, which represent heterogeneity at microscopic levels. Molecular knowledge about those constituents with their localization in such complexity is very crucial for both basic and applied plant sciences. In this context, infrared imaging techniques have advantages over conventional methods to investigate heterogeneous plant structures in providing quantitative and qualitative analyses with spatial distribution of the components. Thus, particularly, with the use of proper analytical approaches and sampling methods, these technologies offer significant information for the studies on plant classification, physiology, ecology, genetics, pathology and other related disciplines. This review aims to present a general perspective about near-infrared and mid-infrared imaging/microspectroscopy in plant research. It is addressed to compare potentialities of these methodologies with their advantages and limitations. With regard to the organization of the document, the first section will introduce the respective underlying principles followed by instrumentation, sampling techniques, sample preparations, measurement, and an overview of spectral pre-processing and multivariate analysis. The last section will review selected applications in the literature.

Correlating molecular spectroscopy and molecular chemometrics to explore carbohydrate functional groups and utilization of coproducts from biofuel and biobrewing processing

Dried distillers grains with solubles (DDGS) was coproducts from bioethanol and biobrewing industry. It was an excellent resource of protein and energy feedstuff in China. Conventional studies often focus on traditional nutritional profiles. To data, there is little research on molecular structure-nutrition interaction of carbohydrate in coproducts. In this study, five kinds of corn-grain based DDGS and two kinds of barley-grain based DDGS were collected from different manufactures in the north of China. They were coded as "1, 2, 3, 4, 5, 6, and 7", respectively. The primary purposes of this project were to investigate the molecular structure-nutrition interaction of carbohydrate in coproducts, in terms of (1) carbohydrate-related chemical composition and nutrient profiles, (2) predicted values for energy in coproducts for animal, and (3) in situ digestion of dry matter. The result showed that acid detergent fiber content in corn DDGS and barley DDGS had negative correlation with structural carbohydrate peak area, cellulose compounds, and carbohydrate component peaks (first, second, and total peak area), which were measured with molecular spectroscopy. The correlation between carbohydrate peak area (second and total) and digestible fiber (tdNDF) were negative. There were no correlation between carbohydrate spectral intensities and energy values, carbohydrate subfractions partitioned by CNCPS system, and in situ rumen degradation. The results indicate that carbohydrate spectral profiles (functional groups) are associated with the carbohydrate nutritive values in coproducts from biofuel and biobrewing processing.

Using ATR-FT/IR to detect carbohydrate-related molecular structure features of carinata meal and their in situ residues of ruminal fermentation in comparison with canola meal

There is no information on the co-products from carinata bio-fuel and bio-oil processing (carinata meal) in molecular structural profiles mainly related to carbohydrate biopolymers in relation to ruminant nutrition. Molecular analyses with Fourier transform infrared spectroscopy (FT/IR) technique with attenuated total reflectance (ATR) and chemometrics enable to detect structural features on a molecular basis. The objectives of this study were to: (1) determine carbohydrate conformation spectral features in original carinata meal, co-products from bio-fuel/bio-oil processing; and (2) investigate differences in carbohydrate molecular composition and functional group spectral intensities after in situ ruminal fermentation at 0, 12, 24 and 48 h compared to canola meal as a reference. The molecular spectroscopic parameters of carbohydrate profiles detected were structural carbohydrates (STCHO, mainly associated with hemi-cellulosic and cellulosic compounds; region and baseline ca. 1483-1184 cm(-1)), cellulosic compounds (CELC, region and baseline ca. 1304-1184 cm(-1)), total carbohydrates (CHO, region and baseline ca. 1193-889cm(-1)) as well as the spectral ratios calculated based on respective spectral intensity data. The results showed that the spectral profiles of carinata meal were significantly different from that of canola meal in CHO 2nd peak area (center at ca. 1091 cm(-1), region: 1102-1083 cm(-1)) and functional group peak intensity ratios such as STCHO 1st peak (ca. 1415 cm(-1)) to 2nd peak (ca. 1374 cm(-1)) height ratio, CHO 1st peak (ca. 1149 cm(-1)) to 3rd peak (ca. 1032 cm(-1)) height ratio, CELC to total CHO area ratio and STCHO to CELC area ratio, indicating that carinata meal may not in full accord with canola meal in carbohydrate utilization and availability in ruminants. Carbohydrate conformation and spectral features were changed by significant interaction of meal type and incubation time and almost all the spectral parameters were significantly decreased (P<0.05) during 48 h ruminal degradation in both carinata meal and canola meal. Although carinata meal differed from canola meal in some carbohydrate spectral parameters, multivariate results from agglomerative hierarchical cluster analysis and principal component analysis showed that both original and in situ residues of two meals were not fully distinguished from each other within carbohydrate spectral regions. It was concluded that carbohydrate structural conformation could be detected in carinata meal by using ATR-FT/IR techniques and further study is needed to explore more information on molecular spectral features of other functional group such as protein structure profile and their association with potential nutrient supply and availability of carinata meal in animals.

Protein structures among bio-ethanol co-products and its relationships with ruminal and intestinal availability of protein in dairy cattle

The objectives of this study were to reveal molecular structures of protein among different types of the dried distillers grains with solubles (100% wheat DDGS (WDDGS); DDGS blend1 (BDDGS1, corn to wheat ratio 30:70%); DDGS blend2 (BDDGS2, corn to wheat ratio 50:50 percent)) and different batches within DDGS type using diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). Compared with BDDGS1 and BDDGS2, wheat DDGS had higher (p < 0.05) peak area intensities of protein amide I and II and amide I to II intensity ratio. Increasing the corn to wheat ratio form 30:70 to 50:50 in the blend DDGS did not affect amide I and II area intensities and their ratio. Amide I to II peak intensity ratio differed (p < 0.05) among the different batches within WDDGS and BDDGS1. Compared with both blend DDGS types, WDDGS had higher α-helix and β-sheet ratio (p < 0.05), while α-helix to β-sheet ratio was similar among the three DDGS types. The α-helix to β-sheet ratio differed significantly among batches within WDDGS. Principal component analysis (PCA) revealed that protein molecular structures in WDDGS differed from those of BDDGS1 and between different batches within BDDGS1 and BDDGS2. The α-helix to β-sheet ratios of protein in all DDGS types had an influence on availability of protein at the ruminal level as well as at the intestinal level. The α-helix to β-sheet ratio was positively correlated to rumen undegraded protein (r = 0.41, p < 0.05) and unavailable protein (PC; r = 0.59, p < 0.05).

Using synchrotron radiation-based infrared microspectroscopy to reveal microchemical structure characterization: frost damaged wheat vs. normal wheat

This study was conducted to compare: (1) protein chemical characteristics, including the amide I and II region, as well as protein secondary structure; and (2) carbohydrate internal structure and functional groups spectral intensities between the frost damaged wheat and normal wheat using synchrotron radiation-based Fourier transform infrared microspectroscopy (SR-FTIRM). Fingerprint regions of specific interest in our study involved protein and carbohydrate functional group band assignments, including protein amide I and II (ca. 1774-1475 cm(-1)), structural carbohydrates (SCHO, ca. 1498-1176 cm(-1)), cellulosic compounds (CELC, ca. 1295-1176 cm(-1)), total carbohydrates (CHO, ca. 1191-906 cm(-1)) and non-structural carbohydrates (NSCHO, ca. 954-809 cm(-1)). The results showed that frost did cause variations in spectral profiles in wheat grains. Compared with healthy wheat grains, frost damaged wheat had significantly lower (p < 0.05) spectral intensities in height and area ratios of amide I to II and almost all the spectral parameters of carbohydrate-related functional groups, including SCHO, CHO and NSCHO. Furthermore, the height ratio of protein amide I to the third peak of CHO and the area ratios of protein amide (amide I + II) to carbohydrate compounds (CHO and SCHO) were also changed (p < 0.05) in damaged wheat grains. It was concluded that the SR-FTIR microspectroscopic technique was able to examine inherent molecular structure features at an ultra-spatial resolution (10 × 10 μm) between different wheat grains samples. The structural characterization of wheat was influenced by climate conditions, such as frost damage, and these structural variations might be a major reason for the decreases in nutritive values, nutrients availability and milling and baking quality in wheat grains.

In-depth study of the protein molecular structures of different types of dried distillers grains with solubles and their relationship to digestive characteristics

BACKGROUND

Dried distillers grains with solubles (DDGS) have been extensively utilised in ruminant rations in western Canada and USA, and it is important to ensure their consistent quality. Traditional chemical methods do not consider the inherent structural changes of feed ingredients. Synchrotron-based Fourier transform infrared microspectroscopy (SFTIRM) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) have been utilised to detect the changes in molecular structure of several feedstuffs (e.g. barley, flaxseed and alfalfa). However, similar structural information is lacking for DDGS. The objectives of this study were to identify differences in protein molecular structures between different grains (wheat, triticale and corn) and DDGS (wheat DDGS, triticale DDGS, corn DDGS and wheat and corn blend DDGS) using SFTIRM and DRIFT and to reveal the relationship between changes in protein molecular structure and the digestive characteristics of the protein in DDGS when fed to dairy cattle.

RESULTS

The protein molecular structure studies showed significant decreases (P < 0.01) in the amide I to amide II ratio and the α-helix to β-sheet ratio between grains and their DDGS. Protein digestive characteristics were correlated with protein molecular structures in grains and DDGS, and prediction equations were established to estimate protein digestive characteristics of DDGS using protein molecular structure parameters. For the DVE/OEB-1994 model, one of the best prediction equations was for truly absorbed protein in the small intestine (DVE) = 296.17 - 38.98 × the amide I to amide II ratio (R(2) = 0.72). For the NRC-2001 system, one of the best prediction equations was for metabolisable protein (MP) = 300.96 - 43.32 × the amide I to amide II ratio (R(2) = 0.76).

CONCLUSION

Protein molecular structure varies between different DDGS and their original grains, and this variation is associated with the digestive characteristics of the proteins in the DDGS and their original grains.

Structural makeup, biopolymer conformation, and biodegradation characteristics of a newly developed super genotype of oats (CDC SO-I versus conventional varieties): a novel approach

Recently, a new "super" genotype of oats (CDC SO-I or SO-I) has been developed. The objectives of this study were to determine structural makeup (features) of oat grain in endosperm and pericarp regions and to reveal and identify differences in protein amide I and II and carbohydrate structural makeup (conformation) between SO-I and two conventional oats (CDC Dancer and Derby) grown in western Canada in 2006, using advanced synchrotron radiation based Fourier transform infrared microspectroscopy (SRFTIRM). The SRFTIRM experiments were conducted at National Synchrotron Light Sources, Brookhaven National Laboratory (NSLS, BNL, U.S. Department of Energy). From the results, it was observed that comparison between the new genotype oats and conventional oats showed (1) differences in basic chemical and protein subfraction profiles and energy values with the new SO-I oats containing lower lignin (21 g/kg of DM) and higher soluble crude protein (530 g/kg CP), crude fat (59 g/kg of DM), and energy values (TDN, 820 g/kg of DM; NE(L3x), 7.8 MJ/kg of DM); (2) significant differences in rumen biodegradation kinetics of dry matter, starch, and protein with the new SO-I oats containing lower EDDM (638 g/kg of DM) and higher EDCP (103 g/kg of DM); (3) significant differences in nutrient supply with highest truly absorbed rumen undegraded protein (ARUP, 23 g/kg of DM) and total metabolizable protein supply (MP, 81 g/kg of DM) from the new SO-I oats; and (4) significant differences in structural makeup in terms of protein amide I in the endosperm region (with amide I peak height from 0.13 to 0.22 IR absorbance unit) and cellulosic compounds to carbohydrate ratio in the pericarp region (ratio from 0.02 to 0.06). The results suggest that with the SRFTIRM technique, the structural makeup differences between the new genotype oats (SO-I) and two conventional oats (Dancer and Derby) could be revealed.