ATR-FTIR spectroscopy and chemometric analysis applied to discrimination of landrace maize flours produced in southern Brazil

Physicochemical and nutritional profiles of wild adlay (Coix lacryma-jobi Linn) accessions by GC, FTIR, and spectrophotometer

Purpose of current study was to determine physicochemical, triglyceride composition, and functional groups of wild adlay accessions (brown, black, yellow, grey, green, off white, and purple) to find out its scope as cereal crop. Triglycerides, minerals and functional groups were determined through Gas chromatography, spectrophotometer and Fourier Transform Infrared (FTIR) spectrophotometer respectively. Results revealed variation among bulk densities, specific densities, percent empty spaces, and corresponding grain counts per 10 g of sample are useful in distinguishing brown, black, yellow, grey, green, off white, and purple wild adlay accessions. Specific density and grain count per 10 g sample was significantly related. No statistical relationship exists among the pronounced physical characteristics. Brown adlay expressed the highest protein, fat, and fiber contents 15.82%, 4.76% and 2.37% respectively. Protein, fat, ash, and fiber percent contents were found comparable to cultivated adlay. Spectrophotometric analysis revealed macro elements including phosphorus, potassium, calcium, and sodium in the range 0.3% - 2.2% and micro elements boron, iron, copper, zinc, and manganese in the range 1.6 mg/kg - 20.8 mg/kg. Gas chromatography showed polyunsaturated fatty acids (PUFA) constitute the primary fraction (39% ± 7.2) of wild adlay triglycerides. Linoleic and palmitic acids were present as prominent fatty acids, 43.5% ±1.4 and 26.3% ±1.4 respectively. Infra-red frequencies distinguished functional groups in narrow band and fingerprint region of protein in association with out of plane region leading to structural differences among adlay accessions. Comparison of major distinguishing vibrational frequencies among different flours indicated black adlay containing highest functional groups appeared promising for varietal development.

Novel infrared puffing: Effect on physicochemical attributes of puffed rice (Oryza sativa L.)

The effect of novel infrared (IR) puffing and various IR powers (350, 450, and 550 Watts [W]) at various distances (10, 20, and 30 cm) on physicochemical characteristics of puffed rice (puffing properties, color, total phenolic content [TPC], antioxidant activity, peroxide value, and morphology) was investigated. By reducing the distance and increasing the IR power, the volume puffing was significantly increased (p < .05), and bulk density was significantly decreased (p < .05) but there was no significant difference in the length/breadth ratio. The IR puffing effect on color, the TPC, antioxidant activity, and food compounds' analysis through Fourier transform infrared (FTIR) spectra were significant (p < .05) during IR puffing. The scanning electron microscopy (SEM) images showed that by increasing the IR power and decreasing the sample distance from the IR source, the size of protrusions was increased (the volume of the protrusions). The maximum increase in the protrusions size was observed in 10 cm distance and 550 W power of IR. This is the first report on the IR puffing of rice and according to the results, the IR puffing technology has a high efficiency at the rice puffing.

Effect of Green Food Processing Technology on the Enzyme Activity in Spelt Flour

In this research, a new approach to enzyme inactivation in flour was presented by supercritical technology, considered a sustainable technology with lower energy consumption compared to other technologies that use ultra-high temperature processing. Total protein concentration and the activity of enzymes α-amylase, lipase, peroxidase, polyphenol oxidase, and protease were determined in flour pre-treated with scCO₂. During the study, it was observed that the activity of enzymes such as lipase and polyphenol oxidase, was significantly reduced under certain conditions of scCO₂ treatment, while the enzymes α-amylase and protease show better stability. In particular, polyphenol oxidase was effectively inactivated below the 60% of preserved activity at 200 bar and 3 h, whereas α-amylase under the same conditions retained its activity. Additionally, the moisture content of the scCO₂-treated spelt flour was reduced by 5%, and the fat content was reduced by 58%, while the quality of scCO₂-treated flour was maintained. In this regard, the sustainable scCO₂ process could be a valuable tool for controlling the enzymatic activity of spelt flour since the use of scCO₂ technology has a positive effect on the quality of flour, which was verified by the baking performance of spelt flour with the baked spelt bread as an indicator of quality.

Cold Atmospheric Pressure Plasma Treatment of Maize Grains-Induction of Growth, Enzyme Activities and Heat Shock Proteins

Zea mays L. is one of the most produced crops, and there are still parts of the world where maize is the basic staple food. To improve agriculture, mankind always looks for new, better methods of growing crops, especially in the current changing climatic conditions. Cold atmospheric pressure plasma (CAPP) has already showed its potential to enhance the culturing of crops, but it still needs more research for safe implementation into agriculture. In this work, it was shown that short CAPP treatment of maize grains had a positive effect on the vitality of grains and young seedlings, which may be connected to stimulation of antioxidant and lytic enzyme activities by short CAPP treatment. However, the prolonged treatment had a negative impact on the germination, growth, and production indexes. CAPP treatment caused the increased expression of genes for heat shock proteins HSP101 and HSP70 in the first two days after sowing. Using comet assay it was observed that shorter treatment times (30-120 s) did not cause DNA damage. Surface diagnostics of plasma-treated grains showed that plasma increases the hydrophilicity of the surface but does not damage the chemical bonds on the surface.

Exploratory and discriminant analysis of plant phenolic profiles obtained by UV-vis scanning spectroscopy

Some species of cover crops produce phenolic compounds with allelopathic potential. The use of math, statistical and computational tools to analyze data obtained with spectrophotometry can assist in the chemical profile discrimination to choose which species and cultivation are the best for weed management purposes. The aim of this study was to perform exploratory and discriminant analysis using R package specmine on the phenolic profile of Secale cereale L., Avena strigosa L. and Raphanus sativus L. shoots obtained by UV-vis scanning spectrophotometry. Plants were collected at 60, 80 and 100 days after sowing and at 15 and 30 days after rolling in experiment in Brazil. Exploratory and discriminant analysis, namely principal component analysis, hierarchical clustering analysis, t-test, fold-change, analysis of variance and supervised machine learning analysis were performed. Results showed a stronger tendency to cluster phenolic profiles according to plant species rather than crop management system, period of sampling or plant phenologic stage. PCA analysis showed a strong distinction of S. cereale L. and A. strigosa L. 30 days after rolling. Due to the fast analysis and friendly use, the R package specmine can be recommended as a supporting tool to exploratory and discriminatory analysis of multivariate data.

Effects of physicochemical and structural properties of single and double feedstuffs derived from different botanic sources on in vitro starch digestion and glucose release kinetics

Starch is the largest constituent in animal diets. The aims of this study were as follows: (a) to assess the variability of basic physicochemical properties and in vitro starch digestion of starchy feedstuffs and investigate relationship between physicochemical properties and starch digestion of the feedstuffs, and (b) to explore the effects of different sources of starchy feedstuffs on starch digestion and glucose release. In this study, we determined the inherent molecular structure and granular structure of starch and chemical compositions of seven starchy feedstuffs, as well as starch digestion in single feedstuff and different feedstuffs combined with corn. Scanning electron microscope (SEM) results revealed significant difference between granule shape and size of starch of different feedstuffs. Fourier transforms infrared (FTIR) spectra for barley and wheat had lower (p < 0.05) absorbance band at areas A_860 and A_928 than other feedstuffs, yet rice starch had the lowest value for ratio (R) (1047/1022). Moreover, digestion rate ranged from 0.0157/min for resistant starch (sorghum) to 0.029/min for rapidly starch (broken rice). The principle component analysis (PCA) showed that predicted glycaemic index (pGI) was positively related to A_1022, glucose and rapidly (RDS) content and negatively related to A_995, A_1047, R (1047/1022), resistant starch (RS) and amylose content. Most of the feedstufss with corn combination had no effect on rate of starch digestion. In addition, different starchy feeds and corn combination changed the rate of starch digestion, when barley, however, sorghum combined with corn seemed to affect rate of starch digestion. To sum up, different sources differed in basic physicochemical and structural properties, which would influence the digestion rate of starch and the release of glucose. Combination of different feedstuffs particular sorghum with corn has interactive effect on starch digestion and the release of glucose.

Latex balloons do not degrade uniformly in freshwater, marine and composting environments

Latex balloons are a poorly-studied aspect of anthropogenic pollution that affects wildlife survival, aesthetic value of waterways, and may adsorb and leach chemicals. Pure latex needs to be vulcanised with sulphur and requires many additional compounds to manufacture high quality balloons. Yet, balloons are often marketed as "biodegradable", which is confusing to consumers. Due to the persistence of latex balloons in the environment and the lethal, documented threat to wildlife, degradation behaviours of latex balloons were quantified in freshwater, saltwater and industrial compost. Using the metrics mass change, ultimate tensile strength (UTS) and superficial composition via attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), latex balloon degradation was documented for 16 weeks. Overall, latex balloons retained their original shape and size. Composted balloons lost 1-2% mass, but some balloons in freshwater gained mass, likely due to osmotic processes. Balloons' UTS decreased from 30.7 ± 10.8-9.5 ± 4.1 Newtons in water, but remained constant (34.3 ± 13.4 N) in compost. ATR-FTIR spectra illustrated compositional and temporal differences between treatments. Taken together, latex balloons did not meaningfully degrade in freshwater, saltwater, or compost indicating that when released into the environment, they will continue to contribute to anthropogenic litter and pose a threat to wildlife that ingest them.

Modelling the vigour of maize seeds submitted to artificial accelerated ageing based on ATR-FTIR data and chemometric tools (PCA, HCA and PLS-DA)

The main goals of this research were to use ATR-FTIR spectroscopy associated with multivariate analyses to identify biochemical changes in high and low vigour seed tissues (embryo and endosperm) in response to accelerated ageing and to create a model to predict seed vigour based on spectroscopic data. High-vigour seeds undergo minimal changes in biochemical composition during stress by accelerated ageing while low-vigour seeds are more sensitive to stress and this lower tolerance is associated with reduced lipid and protein content and increased amino acids, carbohydrates and phosphorus compounds in the embryo. High-vigour seeds show an increase in peaks associated with amino acids and phosphorous compounds in the endosperm after 24 h of stress while low-vigour seeds present these high-intensity peaks only after 72 h in the embryo. The results of this research provide the theoretical basis for the genetic improvement of maize cultivars that aim at higher physiological seed quality.

Effect of surfactant treatment on swelling behaviour of normal and waxy cereal starches

Starch swelling behaviour greatly affects its functionality in a food matrix. For some granular starches pre-treatment with the surfactant, sodium dodecyl sulphate, is known to dramatically affect swelling behaviour. The purpose of this study was to assess the effect of this surfactant treatment on the swelling behaviour of a variety of waxy and normal cereal starches. A concurrent mid-infrared spectroscopy study was carried out to investigate the chemical nature of variations in swelling behaviour. The native normal starches (amylose content 23-28%) showed significant variation in their pasting properties, which was largely eliminated by surfactant treatment. Surfactant treatment had less effect on the behaviour of the waxy starches (amylose contents 1-8%), which still exhibited some residual variation. Waxy durum appeared to be unique within the waxy starches, behaving more similarly to the normal starches. The spectroscopic data highlighted the carbohydrate fingerprint region as the main source of variation between samples.

Phenolic content and ferric reducing-antioxidant power of cow's milk produced in different pasture-based production systems in southern Brazil

BACKGROUND

Phenolic compounds are widely present in forage. However, few studies have been carried out to investigate the presence of these compounds in animal products such as milk. In this study, the total phenolic content (TPC) and ferric reducing-antioxidant power (FRAP) of milk produced under agroecological and conventional management systems in southern Brazil were determined. Three systems were compared: (a) agroecological, with intensive rotational grazing, also known as Voisin grazing (ECO); (b) semi-intensive conventional (SIC); and (c) conventional grazing (CGR) (n = 8 per group). Pastures with distinct and more diverse botanical composition were observed on the ECO farms.

RESULTS

Significantly (P < 0.05) lower amounts of TPC were found in agroecologically produced milk in autumn and summer and the CGR system showed the highest FRAP value (P < 0.05) for the samples collected in autumn. Positive correlations where found between the TPC and FRAP values obtained for the milk samples (0.198, P < 0.05), milk FRAP and forage TPC values (0.344, P < 0.05), and the TPC and FRAP values obtained for the forage (0.70, p < 0.01). PCA applied to the UV spectra dataset (200-350 nm) clearly distinguished the samples collected from the ECO system in the winter.

CONCLUSION

Our results revealed that, under the conditions prevalent in southern Brazil, since the cows were allowed to graze in all of the systems, the TPC and antioxidant capacity of the milk samples showed minimal variation. However, since the forage TPC and FRAP values for the milk were correlated, TPC appears to be a promising variable for the purpose of monitoring forage prior to its selection aimed at enhancing the antioxidant activity of milk.

Carotenoid and anthocyanin contents of grains of Brazilian maize landraces

BACKGROUND

Carotenoid and anthocyanin contents of 26 maize landraces cultivated in southern Brazil were determined to evaluate their potential as natural colorants or functional food ingredients.

RESULTS

The major carotenoids detected in the whole grain flour were zeaxanthin and lutein. Anthocyanins of landraces with purple starchy endosperm (Lingua de Papagaio and Mato Grosso Palha Roxa) were more extractable in methanol-HCl (1%, v/v), exhibiting 2.45 and 0.94 g kg(-1) of whole grains flour, respectively. In contrast, butanol-HCl (30%, v/v) was more effective for the extraction of anthocyanins from the purple-colored landraces Roxo 29 and Roxo 41; genotypes with pigments localized in the outer parts (pericarp) of grains (2.60 and 2.19 g kg(-1)). The Roxo 41 landrace showed the highest concentration of pigments, e.g. 11.72 10(-3) g kg(-1) of total carotenoids and 2.16 g kg(-1) of total anthocyanins. Similarly, the yellow-colored MPA 1 and the purple-colored Roxo 29 landraces showed prominent amounts of carotenoids (10.86 10(-3) g kg(-1)) and anthocyanins (2.60 g kg(-1)), respectively.

CONCLUSION

Our findings suggest that the colored grains of maize landraces studied may hold promise for the development of grain-based functional foods or natural colorants regarding their carotenoid and anthocyanin contents and as genetic resource in breeding programs.