Phenolic acid composition and antioxidant activity of hard red winter wheat varieties

Greek Landrace Flours Characteristics and Quality of Dough and Bread

Besides organic growing, ancient wheats and landraces are attracting the attention of scientists who are reassessing the healthy and dietary properties attributed to them by popular tradition. A total of eleven wheat flours and whole meal samples were analyzed, of which, nine originated from the organic farming of five Greek landraces (one einkorn, one emmer, two durum, and one soft wheat) and a commercial organically grown emmer cultivar. Two commercial conventional flours of 70% and 100% extraction rate were examined for comparison purposes. Chemical composition, micronutrients, phenolic profile, and quantification, and antioxidant activity of all samples were determined. Moreover, dough rheology and breadmaking quality were studied; Flours from local landraces were higher in micronutrients, phenolic content, and antioxidant activity than the commercial samples. The 90% extraction flour of the landrace, besides the highest protein content (16.62%), exhibited the highest content of phenolic acids (19.14 μg/g of flour), whereas the commercial refined emmer flour was the lowest (5.92 μg/g of flour). The same milling of the einkorn landrace also showed a higher specific volume (1.9 mL/g vs. 1.7 mL/g) and lower bread crumb firmness than the whole meal commercial emmer sample (33.0 N vs. 44.9 N). The results of this study showed that the examined Greek wheat landraces could be considered as a possible source of microelements, phenolics, and antioxidants with a beneficial effect in human health, and by using an appropriate breadmaking procedure, they could produce high-quality breads.

Effects of drying methods on bioactive components of Ganoderma lucidum fermented whole wheat in products & in vitro digestive model

The content of bioactive components is the key to determining the quality of Ganoderma lucidum fermented whole wheat (GW) products, and drying is a necessary link in the initial processing of GW, which will affect the bioactivity and quality of GW. This paper was to assess the effect of hot air drying (AD), freeze drying (FD), vacuum drying (VD) and microwave drying (MVD) on the content of bioactive substances and the characteristics of digestion and absorption of GW. The results showed that FD, VD and AD were beneficial to the retention of unstable substances such as adenosine, polysaccharide and triterpenoid active components in GW, and their contents were 3.84-4.66 times, 2.36-2.83 times and 1.15-1.22 times of MVD, respectively. The bioactive substances in GW were released during digestion. The bioavailability of polysaccharides in the MVD group (419.91 %) was significantly higher than that in the FD, VD and AD groups (68.74 %-78.92 %), but their bioaccessibility (5.66 %) was lower than that in the FD, VD and AD groups (33.41 %-49.69 %). Principal component analysis (PCA) showed that VD is more suitable for GW drying due to the comprehensive performance of 3 aspects in terms of active substance retention, bioavailability and sensory quality.

Accumulation of Wheat Phenolic Acids under Different Nitrogen Rates and Growing Environments

The health benefits of whole wheat grains are partially attributed to their phenolic acid composition, especially that of trans-ferulic acid (TFA), which is a powerful natural antioxidant. Breeders and producers are becoming interested in wheat with enhanced health-promoting effects. This study investigated the effects of different nitrogen (N) application rates (0, 42, 84, 126, and 168 N kg ha^-1) on the phenolic acid composition of three wheat varieties in four locations for two years. The results indicate that the different N rates did not affect the TFA concentration but that they significantly affected the concentrations of para-coumaric acid, sinapic acid, and cis-ferulic acid in the wheat grains. A statistical analysis suggested that the wheat phenolic acid composition was predominantly determined by wheat variety, though there existed some interaction effect between the wheat variety and environments. The TFA concentration of the variety Jimai 22 was generally higher (with a mean value of 726.04 µg/g) but was easily affected by the environment, while the TFA concentration of the variety Zhongmai 578 (with a mean value of 618.01 µg/g) was more stable across the different environments. The results also suggest that it is possible to develop new wheat varieties with high yield potential, good end-use properties, and enhanced nutraceutical values.

A comprehensive review of wheat phytochemicals: From farm to fork and beyond

The health benefits of whole wheat consumption can be partially attributed to wheat's phytochemicals, including phenolic acids, flavonoids, alkylresorcinols, carotenoids, phytosterols, tocopherols, and tocotrienols. It is of increasing interest to produce whole wheat products that are rich in bioactive phytochemicals. This review provides the fundamentals of the chemistry, extraction, and occurrence of wheat phytochemicals and includes critical discussion of several long-lasting issues: (1) the commonly used nomenclature on distribution of wheat phenolic acids, namely, soluble-free, soluble-conjugated, and insoluble-bound phenolic acids; (2) different extraction protocols for wheat phytochemicals; and (3) the chemistry and application of in vitro antioxidant assays. This review further discusses recent advances on the effects of genotypes, environments, field management, and processing techniques including ultrafine grinding, germination, fermentation, enzymatic treatments, thermal treatments, and food processing. These results need to be interpreted with care due to varied sample preparation protocols and limitations of in vitro assays. The bioaccessibility, bioavailability, metabolism, and potential health benefits of wheat phytochemicals are also reviewed. This comprehensive and critical review will benefit scientific researchers in the field of bioactive compounds of cereal grains and also those in the cereal food industry to produce high-quality functional foods.

Effect of environment and field management strategies on phenolic acid profiles of hard red winter wheat genotypes

BACKGROUND

Integrated wheat management strategies can affect grain yield and flour end-use properties. However, the effect of integrated management and its interaction with environmental factors on the phenolic acid profiles of wheat has not been reported. The phenolic acid profile has become another parameter for the evaluation of wheat quality due to its potential health benefits.

RESULTS

Year × location × management and year × management × genotype interactions were significant for the total phenolic content (TPC) of wheat samples. The year × location × management × genotype interaction was significant for the concentration of trans-ferulic acid and several other phenolic acids. Field management practices with no fungicide application (e.g., farmer's practice, enhanced fertility) may lead to increased accumulation of phenolic compounds, especially for WB4458, which is more susceptible to fungi infection. However, this effect was also related to growing year and location. Higher soil nitrogen content at sowing also seems to affect the TPC and phenolic acid concentration positively.

CONCLUSION

Wheat phenolic acid profiles are affected by genotype, field management, environment, and their interactions. Intensified field management, in particular, may lead to decreased concentration of wheat phytochemicals. The level of naturally occurring nitrogen in the soil may also affect the accumulation of wheat phytochemicals. © 2021 Society of Chemical Industry.

Wheat grain phenolics: a review on composition, bioactivity, and influencing factors

Wheat (Triticum aestivum L.) is a widely cultivated crop and one of the most commonly consumed food grains in the world. It possesses several nutritional elements. Increasing attention to wheat grain phenolics bioactivity is due to the increasing demand for foods with natural antioxidants. To provide a comprehensive understanding of phenolics in wheat grain, this review first summarizes the phenolics' form and distribution and the phenolic components identified in wheat grain. In particular, the biosynthesis path for phenolics is discussed, identifying some candidate genes involved in the biosynthesis of phenolic acids and flavonoids. After discussing the methods for determining antioxidant activity, the effect of genotypes, environmental conditions, and cultivation systems on grain phenolic component content are explored. Finally, the bioavailability of phenolics under different food processing method are reported and discussed. Future research is recommended to increase wheat grain phenolic content by genetic engineering, and to improve its bioavailability through proper food processing. © 2021 Society of Chemical Industry.

Effects of Different Pilot-Scale Milling Methods on Bioactive Components and End-Use Properties of Whole Wheat Flour

The health benefits from consumption of whole wheat products are widely recognized. This study investigated the effects of different pilot-scale milling methods on physicochemical properties, bioactive components, Chinese steamed bread (CSB), and Chinese leavened pancakes (CLP) qualities of whole wheat flour (WWF). The results indicated that WWF-1 from the reconstitution of brans processed by a hammer mill had the best CSB and CLP quality overall. WWF from entire grain grinding by a jet mill (65 Hz) contained the highest concentration of bioactive components including dietary fibers (DF) and phenolic acids. A finer particle size did not necessarily result in a higher content of phenolic antioxidants in WWF. DF contents and damaged starch were negatively correlated with CSB and CLP quality. Compromised reduced quality observed in CLP made from WWF indicated its potentially higher acceptance as a whole-grain product.

Potential bioaccessibility of phenolic acids in whole wheat products during in vitro gastrointestinal digestion and probiotic fermentation

Health benefits of whole wheat products are partially attributed by their unique phenolic compounds. This study investigated effect of simulated gastrointestinal digestion and probiotic fermentation on releasing of phenolic acids from whole wheat foods (bread, cookie, and pasta). Kinetics results showed that more phenolic acids were released within the first hour of gastric and intestinal digestions compared to the prolonged digestion. Lactobacillus rhamnosus GG, a common probiotic strain, released additional phenolic acids from the digestive residues during fermentation. Simulated digestion released more soluble trans-ferulic acid than chemical extraction in breads (17.69 to 102.71 µg/g), cookie (15.81 to 54.43 µg/g), and pasta (4.88 to 28.39 µg/g). Phenolic acid composition of whole wheat products appeared to be better estimated by digestion methods than the chemical extraction method. The unique insoluble-bound nature and fermentability of wheat phenolic acids may lead to a mechanistic understanding of whole grain consumption for potential colorectal cancer prevention.

Changes in phenolic profiles and antioxidant activities during the whole wheat bread-making process

Health benefits of whole wheat products are partially attributed to their unique phenolic profiles. This study investigated the effect of bread-making processes on the phenolic profiles and antioxidant activities of four different varieties of hard red winter wheat. The fermentation process generally increased soluble phenolic content, flavonoid content, antioxidant activities, and soluble ferulic acid of whole wheat products. The baking process increased the soluble phenolic content and antioxidant activities. Some phenolic acids were incorporated into Maillard reaction products during baking. For the insoluble fraction, fermentation and baking slightly increased phenolic content, flavonoid content, and antioxidant activities of certain wheat varieties. Ferulic acid and isomers of di-ferulic acid (DFA) were not significantly affected by the baking process. Overall, the bread-making process demonstrated positive effects on the potential health benefits of whole wheat products.

Bioactive Components and Health Beneficial Properties of Whole Wheat Foods

Epidemiological studies have found that whole wheat consumption is inversely associated with the risk of chronic diseases, such as obesity, type 2 diabetes, cardiovascular diseases, and cancer. The health benefits of whole wheat foods are attributed to their bioactive components, including phytochemicals and dietary fiber. In this review, the current studies regarding bioactive components and their health-promoting roles and the underlying mechanisms were summarized and discussed. The current research advances in processing technologies capable of potentially enhancing the nutritional quality of wheat and wheat-based foods were also included. This review may promote the research, development, and consumption of whole wheat foods in reducing the risk of human chronic diseases.

Rapid determination of total phenolic content of whole wheat flour using near-infrared spectroscopy and chemometrics

Phenolics in whole wheat products provide many health benefits. Wheat breeders, producers, and end-users are becoming increasingly interested in wheats with higher total phenolic content (TPC). Whole wheat flour with higher phenolics may have greater marketing value in the future. However, conventional methods determining TPC are costly and labor-intensive, which are not practical for wheat breeders to analyze several thousands of lines within a limited timeframe. We presented a novel application of near-infrared spectroscopy for TPC prediction in whole wheat flour. The optimal regression model demonstrated R² values of 0.92 and 0.90 for the calibration and validation sets, and a residual prediction deviation value of 3.4. The NIR method avoids the tedious extraction and TPC assay procedures, making it more convenient and cost-effective. Our result also demonstrated that NIR can accurately quantify phenolics even at low concentration (less than 0.2%) in the food matrix such as whole wheat flour.

Changes in Bread Quality, Antioxidant Activity, and Phenolic Acid Composition of Wheats During Early-Stage Germination

This study reported changes in baking properties, total phenolic content (TPC), antioxidant activity, and phenolic acid composition of three hard red winter wheat varieties during the early stage of seed germination. The wheats were sprouted at 30 °C and 95% relative humidity to achieve different germination levels based on falling number ranges (550 s for control flour; 350 s [low], 250 s [medium], and 120 s [high] for sprouted flours, respectively). Average germination times were 7, 8, and 10 hr for the low, medium, and high germinated samples, respectively. Most baking properties of sprouted whole flour were comparable to the control flour. However, TPC, flavonoid content, phenolic acids, and antioxidant activity of sprouted flour were lower than the control flour. To our knowledge, this is the first study that reported both baking properties and antioxidant potential of sprouted whole wheat flour from early-stage germination. The study deepens the understanding of seed germination and the potential use of sprouted flour in baking industry. PRACTICAL APPLICATION: This study evaluates the baking quality and nutraceutical value of sprouted whole wheat flour, which are key factors determining the application of sprouted flour in the baking industry. The results will contribute to the production of quality bakery products with enhanced nutraceutical benefits.