Effect of infrared roasting on antioxidant activity, phenolic composition and Maillard reaction products of Tartary buckwheat varieties

Rutin distribution in Tartary buckwheat: Identifying prime dietary sources through comparative analysis of post-processing treatments

Rutin is a crucial bioactive compound that determines the nutritional value of Tartary buckwheat (TB). However, the potential of utilizing TB as a dietary source of rutin for human consumption remains largely unexplored. This study aims to address these knowledge gaps by conducting a detailed analysis of rutin content distribution in TB tissues. Our findings revealed a significant variation in rutin content across different plant tissues. Notably, higher levels of rutin were found in embryos and cotyledons compared to other tissues, highlighting them as the primary sites of rutin accumulation in TB seeds and sprouts. Additional research on the processing of TB showed that sprouts and seeds retain high rutin levels even after boiling, steaming, deep-frying, stir-frying, and popping. Comparative analysis of different TB-derived products confirmed that cooked seeds and sprouts can serve as significant dietary sources of rutin. This study offers a foundational framework for the development of future dietary recommendations and applications of TB.

Nutritional, Chemical, and Functional Properties of Wholegrain Einkorn Pasta Through Cooking and Digestion: A Comparative Study with Wholegrain Durum Wheat Pasta

Despite growing interest in ancient wheat varieties, the functional and nutritional properties of einkorn (Triticum monococcum) in cereal-based foods remain not fully elucidated. This study examined the chemical composition and functional properties of wholegrain einkorn pasta through cooking and simulated gastrointestinal digestion, comparing it with conventional Triticum durum wheat pasta. While sharing similar macronutrient profiles, einkorn pasta demonstrated higher retention of key compounds including phenolics, tocopherols, and phytosterols throughout cooking and in vitro digestion. Notable findings include enhanced prebiotic activity specifically targeting bifidobacteria populations and preserved antioxidant capacity despite thermal processing. These results demonstrated einkorn's potential as a functional food ingredient, suggesting its capacity to deliver enhanced nutritional benefits through its unique matrix properties. Our findings provide mechanistic insights into ancient grain functionality in modern food applications, with implications for developing nutritionally enhanced pasta products.

Retention of bioactive compounds during technological steps of the production of bread enriched with roasted buckwheat hulls

The retention of bioactive compounds in the blend of wheat and rye flours and 4% roasted buckwheat hulls, dough before and after fermentation, and obtained bread were determined. In parallel, the content of Maillard reaction products (MRPs) and antioxidant capacity (AC) during technological steps of bread production were studied. The dough formation and fermentation process increased the content of phenolic acids and flavonoids and reduced the content of tocopherols, and no changes in glutathione as compared to the blend were noted. Moreover, the increased level of available lysine and AC were observed after dough fermentation. The baking process resulted in further increased phenolic acids, and flavonoids and decreased the tocopherols and glutathione contents. The bread was characterized by the highest values of parameters related to MRPs, such as the content of fluorescent intermediary compounds and final browning index compared to other analyzed steps.

Effects of Roasting on Antibacterial and Antioxidant Properties of Sophora japonica Buds-The Involvements of Rutin and Quercetin Constituents

Roasting is the most common thermal processing method established for Sophora japonica (SJ) buds applied as traditional medicines, and it has also been reported to alter several of their therapeutic functions. However, there have been no studies investigating the influences of roasting on the effects of these materials against bacteria. Therefore our study was performed to examine the alterations that this process would induce in SJ buds' antibacterial properties. Fresh buds were subjected to hot air drying or different roasting methods, as described in Materia Medica, including yellow-, dark yellow-, scorched-, and charred-roasting conditions. Antibacterial effects, total polyphenol and flavonoid contents, antioxidant activities, as well as rutin and quercetin concentrations in methanol extracts obtained from those materials, were then measured and compared. The results showed that dark yellow-roasted SJ buds exerted the strongest antibacterial and antioxidant activities and were also the richest in polyphenol contents. Analysis of rutin and quercetin revealed that, following the increment in heating temperatures up to 240 °C, the reduction in rutin content occurred in a parallel manner to the increment in quercetin content. However, overheating at 300 °C reduced both concentrations. Among the five tested samples, dark yellow-roasted SJ had the highest amounts of quercetin. Furthermore, the comparison of rutin and quercetin in antibacterial effects and antioxidant activities showed that the latter was significantly stronger in both of these functions, suggesting that the increment in quercetin content as a result of heat treatment was responsible, at least in part, for the potentiation of the two therapeutic effects.

Recent Advances in the Health Benefits of Phenolic Acids in Whole Grains and the Impact of Processing Techniques on Phenolic Acids: A Comprehensive Review

Phenolic acids, essential compounds in whole grains, are renowned for their health-enhancing antioxidant and anti-inflammatory properties. Variations in concentration, particularly of hydroxybenzoic and hydroxycinnamic acids, are observed among grain types. Their antiobesity and antidiabetes effects are linked to their modulation of key signaling pathways like AMPK and PI3K, crucial for metabolic regulation and the body's response to inflammation and oxidative stress. Processing methods significantly influence phenolic acid content and bioavailability in whole grains. Thermal techniques like boiling, baking, or roasting can degrade these compounds, with loss influenced by processing conditions. Nonthermal methods such as germination, fermentation, or their combination, can protect or enhance phenolic acid content under ideal conditions. Novel nonthermal approaches like ultrahigh pressure (UHP), irradiation, and pulsed electric fields (PEF) show promise in preserving these compounds. Further research is needed to fully comprehend the impact mechanisms of these innovative methods on the nutritional and sensory attributes of cereals.

Effect of GABA combined with ultrasound stress germination treatment on phenolic content and antioxidant activity of highland barley

BACKGROUND

This study investigated the effects of γ-aminobutyric acid (GABA) combined with ultrasonic stress germination (AUG) treatment on the phenolic content and antioxidant activity of highland barley (HB). Key variables, including germination times (ranging from 0 to 96 h), ultrasonic power (200-500 W), and GABA concentration (5-20 mmol/L), were optimized using response surface methodology (RSM) to enhance the enrichment of phenolic compounds. Furthermore, the study assessed the content, composition, and antioxidant activities of phenolic compounds in HB under various treatment conditions such as germination alone (G), ultrasonic stress germination (UG), and AUG treatment.

RESULTS

The study identified optimal conditions for the phenolic enrichment of HB, which included a germination time of 60 h, an ultrasound power of 300 W, and a GABA concentration of 15 mmol L-1. Under these conditions, the total phenolic content (TPC) in HB was measured at 7.73 milligrams of gallic acid equivalents per gram dry weight (mg GAE/g DW), representing a 34.96% enhancement compared to untreated HB. Notably, all treatment modalities - G, UG, and AUG - significantly increased the phenolic content and antioxidant activity in HB, with the AUG treatment proving to be the most effective.

CONCLUSION

These obtained results suggest that AUG treatment is a promising processing method for enriching phenolic compounds and improving antioxidant activity in HB. Subsequently, the AUG-treated HB can be used to develop phenolic-rich germinated functional foods to further broaden the application of HB. © 2024 Society of Chemical Industry.

Coffee substitutes: A review of the technology, characteristics, application, and future perspective

Despite being one of the most frequently consumed beverages worldwide, there are concerns that excessive consumption of coffee can have adverse effects, especially concerning the addictive and stimulating effects of the alkaloid caffeine, which contributes to coffee's popularity. It is known to increase the risk of hypertension and heart rate among predisposed individuals, adversely affecting the nervous system. Even though they differ in nature from those found in coffee, coffee substitutes can be considered economically and health-wise as a favorable alternative to natural coffee brews. This review summarizes the state-of-the-art varieties of plants used as coffee substitutes and discusses their production technology, chemical composition, nutritional properties, health benefits, economic challenges, and rationale for choosing the plant as a substitute for coffee. Various instant products and coffee substitute blends are also available on the market especially based on different kinds of plants and herbs like ginger, rye, date pits, quinoa, lupine, chicory, barley, rye, oak, and so on. These coffee substitutes have several advantages especially having no caffeine and containing different beneficial phytochemicals, although the results of the difference between the levels of harmful compounds in coffee and coffee substitutes were contradictory. Therefore, it is no wonder that the development of coffee substitutes, which are beverages that are able to mimic the taste and aroma of coffee, is on the rise at present.

Effect of microwave-assisted treatment on proximate, techno-functional, thermal, structural, and storage properties of TGN (Cyperus esculentus L.) flour

BACKGROUND

The use of the emerging technique of microwave-assisted roasting on TGN (TGN) flour was investigated. Tiger nuts were subjected to microwave irradiation at 450, 600, and 900 W each at 5, 10, and 15 min, and milled to flour. The flours were analyzed for proximate, bioactive, techno-functional, morphological, thermal, and storage effects on their composition. An untreated sample was the control.

RESULTS

The results revealed that microwave treatment significantly (P < 0.05) elicited various modifications in the proximate composition and techno-functional properties. The treatment improved the bioactive composition of phenolic content together with the antioxidant activity of the flour. Progressive microwave treatment of TGNs resulted in flours with darker colors and reduced pasting parameters. Structural modification of starch granules, protein denaturation, and starch-protein complexes occasioned by microwave treatment were evidenced in the functional group analysis, including morphological agglomeration, increased particle size, and thermal properties. Treatment also enhanced the microbiological qualities of flour after 8 weeks of storage.

CONCLUSION

This study shows that microwave treatment produces excellent physical modifications that lead to improvements in the nutritional, functional, sensory, and color properties, and safety attributes of TGN flour for food application. This is a development that could present opportunities for novel food formulation by the food industry and related industries. © 2024 Society of Chemical Industry.

Metabolomics Uncovers the Mechanisms of Nitrogen Response to Anthocyanins Synthesis and Grain Quality of Colored Grain Wheat (Triticum aestivum L.)

Nitrogen (N) is a key factor for plant growth and affects anthocyanin synthesis. This study aimed to clarify the potential mechanisms of N levels (LN, 0 kg·ha-1; MN, 150 kg·ha-1; HN, 225 kg·ha-1) in anthocyanin synthesis and grain quality of colored grain wheat. HN increased the yield component traits and grain morphology traits in colored grain wheat while decreasing the processing and nutrient quality traits. Most quality traits were significantly negatively correlated with the yield composition and morphological traits. Anthocyanin was more accumulated under LN conditions, but other related yield and morphological traits of colored grain wheat declined. The anthocyanin content was the highest in blue wheat, followed by that in purple wheat. Cyanidin-3-O-(6-O-malonyl-β-d-glucoside) and cyanidin-3-O-rutinoside were the predominant anthocyanins in blue and purple wheat. The identified anthocyanin-related metabolites were associated with flavonoid biosynthesis, anthocyanin biosynthesis, and secondary metabolite biosynthesis. Therefore, the study provided information for optimizing nitrogen fertilizer management in producing high quality colored wheat and verified the close relationship between anthocyanin and low N condition.

Change of physiochemical characteristics, nutritional quality, and volatile compounds of Chenopodium quinoa Willd. during germination

The impacts of varying germination periods (0-72 h) on morphological properties, proximate composition, amino acid profile, GABA levels, antioxidant attributes, polyphenol content (both free and bound), and volatile compounds of quinoa were evaluated. Germination significantly increased the content of fiber, amino acids, GABA, polyphenols, and in-vitro antioxidant activities in quinoa. The optimal nutritional quality and antioxidant capacity of quinoa were observed during the 36-72 h germination period. We examined the dynamics of 47 phenolic compounds in quinoa during germination and noted a substantial rise in free phenolic acids and bound flavonoids post-germination. A total of 53 and 84 volatile compounds were respectively identified in ungerminated quinoa and germinated quinoa. It was found that the germination period of 24-48 h contributed to reducing the presence of undesirable flavors. TEM analysis revealed significant structural damage to the ultrastructure and relaxation of the cell wall in germinated quinoa grains.

Effects of roasting and steeping on nutrients and physiochemical compounds in organically grown naked barley teas

Barley tea, a popular beverage with cultural traditions in East Asia, has long been esteemed for its flavor, aroma, thirst-quenching properties and perceived health benefits attributed to bioactive compounds. This study investigated the nutritional, bioactive, and antioxidant aspects of three commercial naked barley varieties, focusing on the impact of roasting and subsequent steeping for tea. Roasting did not affect total dietary fiber or β-glucan content. The process reduced sugar content and led to the disappearance of free amino acids, contributing to high levels of acrylamide and color changes. Roasting diminished total phenolic compounds, particularly flavonoids, resulting in reduced antioxidant activity. Metabolite analysis identified compounds in roasted grains that could influence tea flavor and aroma. Roasted barley tea made from these varieties was not a source of dietary fiber or antioxidants, but also contained no acrylamide. Therefore, consumers seeking such benefits from barley are urged to consume whole grain foods.

Dry-air roasting impact on physicochemical, functional, antioxidant properties, phenolic profile and Maillard reaction products of flaxseed flour and cake flour

The study investigated and compared physicochemical, functional, antioxidant properties, phenolic profile and Maillard reaction products (MRP) of flaxseed flour (FF) and flaxseed cake flour (FCF) upon dry-air roasting (DaR) of flaxseeds at 140, 160 and 180 °C for 5 and 10 min. This information on FF and FCF is limited and has considerable gaps. The raw FF exhibited higher fat, ash, antioxidant and functional properties while lower protein than the FCF. Upon increasing DaR conditions, the ash and protein increased in FCF and decreased in FF. DaR at 180 °C for 10 min augmented water solubility index, ΔE, MRP, free rutin and syringic acid, bound epicatechin, gallic acid and syringic acid while lowered moisture, L*, b*, hue, chroma, potassium, iron, selenium, emulsion indexes, caffeic acid, flavonoids and free resveratrol in FF and FCF. In conclusion, DaR improves phenolic profile, antioxidant properties, MRP, water solubility and oil absorption capacity of FF and FCF.

Cold-Pressed Okra Seed Oil Byproduct as an Ingredient for Muffins to Decrease Glycemic Index, Maillard Reaction, and Oxidation

This study aimed to investigate the effects of adding cold-pressed okra seed oil byproduct (OSB) to the muffin formulation, as a partial substitute for wheat flour, on the nutritional, physicochemical, rheological, textural, and sensory properties of muffins. The carbohydrate, protein, oil, moisture, and ash contents of OSB were 44.96, 32.34, 10.21, 7.51, and, 4.98%, respectively, indicating that OSB was rich in protein and carbohydrate. All muffin samples showed a shear thinning behavior, indicating that the viscosity of all samples decreased with increasing shear rate. The frequency sweep test showed that all samples showed viscoelastic solid-like structure [G' (storage modulus)> G″ (loss modulus)]. The K' values (between 66.45 and 139.14) were higher than the K″ values (between 36.62 and 80.42) for all samples. The result was another indication of the viscoelastic solid characteristic of the samples. In our study, it was found that the fluorescence of advanced Maillard products and soluble tryptophan index decreased with increasing amount of OSB, indicating that OSB addition led to a decrease in the amount of fluorescent Maillard reaction (MR) products. The fortified muffins with more than 10% OSB had a reduced estimated glycemic index (GI) significantly in comparison with control muffin samples (p < 0.05). The induction period (IP) values of the muffin samples containing OSB (between 11:57 and 15:15 h/min) were higher than the IP value of the control sample (10:50 h/min), indicating that OSB improved the oxidative stability of the muffin samples. The addition of OSB has shown no negative effect on sensory attributes considering texture, mouth fell, odor, and taste. This study suggested that the addition of OSB in muffins could improve rheological properties and oxidative stability and decrease GI and the amount of MR products without negative impact on sensory properties.

Effects of degree of milling on nutritional quality, functional characteristics and volatile compounds of brown rice tea

This study investigated the effects of rice preparation using different degrees of milling (DOM) from 0% to 13% on the nutritional composition, functional properties, major volatile compounds and safety of brown rice tea (BRT). We found that 2% DOM reduced 52.33% of acrylamide and 31.88% of fluorescent AGEs. When DOM was increased from 0% to 13%, the total phenolic content (TPC) of brown rice tea decreased by 48.12%, and the total flavonoid content (TFC) and condensed tannin content (CTC) also decreased significantly, with the smallest decrease at 2% DOM. In addition, the inhibitory activities of α-amylase, α-glucosidase and pancreatic lipase as well as the antioxidant activity also decreased gradually. Analysis by electronic nose and gas chromatography-mass spectrometry (GC-MS) showed that alkanes, furans, aldehydes, pyrazines and alcohols were the major volatiles in BRT, with 2% DOM having the greatest retention of aroma compounds. An orthogonal partial least squares discriminant analysis (OPLS-DA) and VIP score (VIP > 1 and p < 0.05) analysis were used to screen 25 flavor substances that contributed to the differences in BRT aroma of different DOMs. These results suggest that 2% milled BRT can improve safety and palatability while maximizing the retention of flavor compounds and nutrients. The findings of this study contribute to an enhanced understanding of the dynamics of changes and preservation of aroma compounds and nutrients present during the processing of BRT.

Complexation of starch and phenolic compounds during food processing and impacts on the release of phenolic compounds

Phenolic compounds can form complexes with starch during food processing, which can modulate the release of phenolic compounds in the gastrointestinal tract and regulate the bioaccessibility of phenolic compounds. The starch-phenolic complexation is determined by the structure of starch, phenolic compounds, and the food processing conditions. In this review, the complexation between starch and phenolic compounds during (hydro)thermal and nonthermal processing is reviewed. A hypothesis on the complexation kinetics is developed to elucidate the mechanism of complexation between starch and phenolic compounds considering the reaction time and the processing conditions. The subsequent effects of complexation on the physicochemical properties of starch, including gelatinization, retrogradation, and digestion, are critically articulated. Further, the release of phenolic substances and the bioaccessibility of different types of starch-phenolics complexes are discussed. The review emphasizes that the processing-induced structural changes of starch are the major determinant modulating the extent and manner of complexation with phenolic compounds. The controlled release of complexes formed between phenolic compounds and starch in the digestive tracts can modify the functionality of starch-based foods and, thus, can be used for both the modulation of glycemic response and the targeted delivery of phenolic compounds.

Wheat Roll Enhanced by Buckwheat Hull, a New Functional Food: Focus on the Retention of Bioactive Compounds

Wheat roll enhanced by buckwheat hull was used as a model for determining the retention of bioactive compounds during technological steps. The research included analysis of the formation of Maillard reaction products (MRPs) and retention of bioactive compounds such as tocopherols, glutathione, or antioxidant capacity. About a 30% decrease in the content of available lysine in the roll was observed compared to the value obtained for fermented dough. Free FIC, FAST index, and browning index were highest for the final products. The increase of analyzed tocopherols (α-, β-,γ-, and δ-T) was noticed during the technological steps, with the highest values found for the roll with 3% of buckwheat hull. A significant reduction in GSH and GSSG content occurred during the baking process. The observed increase in the value of the antioxidant capacity after the baking process may be the result of the formation of new antioxidant compounds.

Application of far-infrared radiation for sun-dried chili pepper (Capsicum annum L.): drying characteristics and color during roasting

BACKGROUND

Chili is hygroscopic and needs a fast-drying method before feeding into pulverizers. The far-infrared radiation (FIR) roasting technique provides various benefits, such as higher drying rates within a short duration, reduction of mycotoxins, and improvement in the textural quality of agricultural produce. In addition, thin-layer modeling supports understanding the drying kinetics of agricultural produce. Therefore, the objective of this research was to study the thin-layer drying characteristics and color of whole chili pod and its components (i.e. seeds, pedicel, and placenta) of sun-dried chili during FIR roasting. The samples were dried at 7.76 μm (100 °C), 6.12 μm (200 °C), 5.056 μm (300 °C), and 4.30 μm (400 °C) by exposing them to FIR in a single layer and the drying kinetics were studied using the Midilli model. Further, the color variation during FIR roasting was studied.

RESULTS

FIR roasting of chili pods and their components (i.e. seeds, pedicel, and placenta) shows a falling rate drying period at each wavelength. The moisture content decreased with decreasing FIR wavelength. The ∆E values for pods, pedicel, and placenta were increased during FIR roasting. The Midilli model results in R² and root-mean-square error value ranges of 0.7563-1.000 and 5 × 10^-8 -0.1238 respectively for the current study. The Midilli model at 300 °C shows that the FIR has minor variation compared with other FIR temperatures.

CONCLUSION

FIR technology can be implemented to roast chili pods and their components (i.e. seeds, pedicel, and placenta) within a short period. Further, the application of FIR for roasting purposes desirably increases the color variation. The Midilli model can effectively describe the drying kinetics of the chili pods and their components during FIR roasting. © 2021 Society of Chemical Industry.

Effects of infrared heating as an emerging thermal technology on physicochemical properties of foods

Infrared (IR) radiation is part of an electromagnetic spectrum between the ultraviolet and microwave regions. IR radiation impacts the surface of the food, generating heat that can be used as an efficient drying technique. Apart from drying, IR heating is an emerging food processing technology with applications in baking, roasting, microbial inactivation, insect control, extraction for antioxidant recovery, peeling, and blanching. Physicochemical properties such as texture, color, hardness, total phenols, and antioxidants capability of foods are essential quality attributes that affect the food quality. In this regard, the main objective of this review study was to highlight and discuss the effects of IR heating on food quality to expand its food applications and commercial adoption. The fundamental mechanisms, type of emitters, and IR processing parameters are discussed in this review to explore their impacts on food quality. Infrared heating has been shown that the appropriate operating conditions (distance, exposure time, IR power, and temperature) with high heat transfer, thus leading to a shorter drying time. Besides, IR heating used in food processing to improve food-surface color and flavor, it also enhances hardness, firmness, shrinkage, crispiness, and viscosity. Meanwhile, antioxidant activity is enhanced, and some nutrients are retained.

Characterization of Saponins from Differently Colored Quinoa Cultivars and Their In Vitro Gastrointestinal Digestion and Fermentation Properties

Quinoa contains rich saponins, which are removed during processing and cause ecological waste. We extracted saponins from quinoa (SEQ) in black, white, and red cultivars and compared their composition by spectrophotometric assay and high-performance liquid chromatography analysis combined with acid hydrolysis. The digestion and fermentation properties of SEQ were investigated using an in vitro model. Our results showed that acid hydrolysis released sapogenins, mainly phytolaccagenin (PA), hederagenin (HD), and oleanolic acid from SEQ. Varying from SEQ in red, SEQ in black and white had a similar composition and content of sapogenins. Gastrointestinal digestion did not release sapogenins from SEQ but reduced the antioxidant activity of SEQ. Gut microbiota from human feces released PA and HD from SEQ. Reciprocally, SEQ in black significantly increased the growth of Lactobacillus spp. and Bifidobacterium spp., while reducing the growth of Shigella spp. The present study provides guidance for further investigation about the bioactivities of saponins from quinoa.

Influence of dry air and infrared pre-treatments on oxidative stability, Maillard reaction products and other chemical properties of linseed (Linum usitatissimum L.) oil

In this study, the influence of dry air and infrared pre-treatments on linseed oil (LO) yield, chemical properties, colour, pigment content, total phenolic content (TPC), Maillard reaction products (MRPs), fatty acid composition (FAC), radical scavenging activity (RSA), and oxidative stability index (OSI) were investigated. An increase in dry air and infrared roasting temperature had increased the LO yield, pigment content, a* value, TPC, RSA, OSI, and browning index (BI) while lowered the L* and b* values of LO. Higher OSI (2.24 h), chlorophylls (2.29 mg/kg), carotenoids (3.87 mg/kg), TPC (63.67 mg GAE/100 g), RSA (62.53%), BI (0.330), and MRPs (2.10 mg/kg) were detected in LO by dry air roasting at 180°C for 10 min. Dry air and infrared roasting had slightly affected the FAC of LO. Both dry air and infrared pre-treatments had influenced the LO quality characteristics. However, dry air roasting of linseed at 180°C for 10 min proved more effective in improving oxidative stability, antioxidant activity and other quality characteristics of LO.

SUPPLEMENTARY INFORMATION

The online version of this article at 10.1007/s13197-021-05023-6.

Effect of oilseed roasting on the quality, flavor and safety of oil: A comprehensive review

Roasting is widely applied in oil processing and employs high temperatures (90-260 °C) to heat oilseeds evenly. Roasting improves the extraction yield of oil by the generation of pores in the oilseed cell walls, which facilitates the movement of oil from oilseed during subsequent extraction. It also affects the nutritional value and palatability of the prepared oil, which has attracted consumers' attention. An appropriate roasting process contributes to better extraction of bioactive compounds, particularly increasing the total polyphenol content in the oil. Correspondingly, extracted oil exhibits higher antioxidant capacity and oxidative stability after roasting the oilseeds due to better extraction of endogenous antioxidants and the generation of Maillard reaction products. Furthermore, roasting process is critical for the formation of aroma-active volatiles and the improvement of desired sensory characteristics, so it is indispensable for the production of fragrant oil. However, some harmful components are inevitably generated during roasting, including oxidation products, polycyclic aromatic hydrocarbons, and acrylamide. Monitoring and controlling the concentrations of harmful compounds in the oil during the roasting process is important. Therefore, this review updates how roasting affect the quality and safety of oils and provides useful insight into regulation of the roasting process based on bioactive compounds, sensory characteristics, and safety of oils. Further research is required to assess the nutritional value and safety of roasted oils in vivo and to develop a customized roasting process for various oilseeds to produce good-quality oils.

From Plantation to Cup: Changes in Bioactive Compounds during Coffee Processing

Coffee is consumed not just for its flavor, but also for its health advantages. The quality of coffee beverages is affected by a number of elements and a series of processes, including: the environment, cultivation, post-harvest, fermentation, storage, roasting, and brewing to produce a cup of coffee. The chemical components of coffee beans alter throughout this procedure. The purpose of this article is to present information about changes in chemical components and bioactive compounds in coffee during preharvest and postharvest. The selection of the appropriate cherry maturity level is the first step in the coffee manufacturing process. The coffee cherry has specific flavor-precursor components and other chemical components that become raw materials in the fermentation process. During the fermentation process, there are not many changes in the phenolic or other bioactive components of coffee. Metabolites fermented by microbes diffuse into the seeds, which improves their quality. A germination process occurs during wet processing, which increases the quantity of amino acids, while the dry process induces an increase in non-protein amino acid γ-aminobutyric acid (GABA). In the roasting process, there is a change in the aroma precursors from the phenolic compounds, especially chlorogenic acid, amino acids, and sugars found in coffee beans, to produce a distinctive coffee taste.

Effects of Airflow Ultrafine-Grinding on the Physicochemical Characteristics of Tartary Buckwheat Powder

Five different ultrafine milled flours (UMFs) were prepared from Tartary buckwheat via airflow ultrafine-grinding at different grinding pressures. The airflow ultrafine-grinding resulted in marked differences in particle size (from 100 to 10 μm). The UMFs were all brighter in appearance (higher L*) than Tartary buckwheat common flour (TBCF). Illustrated by the example of 70 °C, the UMFs were also found to have a greater water holding capacity (from 4.42 g/g to 5.24 g/g), water solubility (from 12.57% to 14.10%), and water solubility index (from 5.11% to 6.10%). Moreover, as the particle sizes reduced, the moisture content decreased (from 10.05 g/100 g DW to 7.66 g/100 g DW), as did the total starch content (from 68.88 g/100 g DW to 58.24 g/100 g DW) and the protein content (from 13.16% to 12.04%). However, the grinding process was also found to have negative effects on the mineral content of the Tartary buckwheat. Additionally, several substantial variations were found in their hydration properties along with grinding pressure changes in the differently ground UMFs. Consequently, fine Tartary buckwheat powders of a bright yellow color, with superior food processing properties, were prepared in this study by airflow ultrafine-grinding.

Bioactive compounds, health benefits, and industrial applications of Tartary buckwheat (Fagopyrum tataricum)

Tartary buckwheat belongs to the family Polygonaceae, which is a traditionally edible and medicinal plant. Due to its various bioactive compounds, the consumption of Tartary buckwheat is correlated to a wide range of health benefits, and increasing attention has been paid to its potential as a functional food. This review summarizes the main bioactive compounds and important bioactivities and health benefits of Tartary buckwheat, emphasizing its protective effects on metabolic diseases and relevant molecular mechanisms. Tartary buckwheat contains a wide range of bioactive compounds, such as flavonoids, phenolic acids, triterpenoids, phenylpropanoid glycosides, bioactive polysaccharides, and bioactive proteins and peptides, as well as D-chiro-inositol and its derivatives. Consumption of Tartary buckwheat and Tartary buckwheat-enriched products is linked to multiple health benefits, e.g., antioxidant, anti-inflammatory, antihyperlipidemic, anticancer, antidiabetic, antiobesity, antihypertensive, and hepatoprotective activities. Especially, clinical studies indicate that Tartary buckwheat exhibits remarkable antidiabetic activities. Various tartary buckwheat -based foods presenting major health benefits as fat and blood glucose-lowering agents have been commercialized. Additionally, to address the safety concerns, i.e., allergic reactions, heavy metal and mycotoxin contaminations, the quality control standards for Tartary buckwheat and its products should be drafted and completed in the future.

Impact of germination on phenolic composition, antioxidant properties, antinutritional factors, mineral content and Maillard reaction products of malted quinoa flour

The study aimed at improving and comparing the nutritional profile of black (BQ) and white quinoa (WQ) through malting at different germination periods (24, 48, 72 and 96 h), followed by drying at 50 °C, decluming, grinding and sieving to obtain malt flour. The changes in protein, reducing sugar, Maillard reaction products (MRPs), minerals, free and bound polyphenols and antioxidant activity were noted. Malting caused significant increase in polyphenolic content, antioxidant capacity and fluorescence of advanced MRP (FAST) index. The highest increment was noted in malts germinated for 48 and 72 h. BQ malts were marked by higher bound hydroxycinnamic acids, flavan-3-ols, magnesium, potassium and antioxidant activity, while, WQ malts had lower saponin, phytic acid but higher protein, iron, calcium, FAST index. WQ exhibited highest increment (27.23%) in antioxidant activity even though it had lower polyphenols than BQ after malting. Major loss in polyphenols and proteins occurred in malt germinated for 96 h.

Effect of quercetin on the in vitro Tartary buckwheat starch digestibility

Tartary buckwheat is one of the few pseudocereals with abundant flavonoids and starch. However, there are different views on the digestibility of Tartary buckwheat starch (TBS) because of its particle size and structure. In this study, fluorescence spectrum methods and enzymatic kinetics were used to investigate the interaction between TBS /two glycosidase (α-amylase and α-glucosidase) and quercetin to explore its digestive properties and provide a perspective regarding the application of TBS in functional starch products. The results showed that the interaction between TBS and quercetin was probably weak hydrophobic force and hydrogen bonding. The inhibitory effect of quercetin on α-amylase was better than that on α-glucosidase. The half inhibitory concentrations (IC₅₀) of quercetin to α-amylase and α- glucosidase was (270 ± 3.31) and (544 ± 9.01) μg/mL, respectively. The intrinsic fluorescence of two enzymes was statically quenched by forming a complex with quercetin. Quercetin also increased the microenvironment hydrophilicity of tryptophan residues in glycosidase. In vitro digestion experiment demonstrated that quercetin and TBS co-gelatinized together was more effective to inhibit TBS hydrolysis than quercetin itself alone. In the first-order kinetic and LOS model, quercetin-starch gel structure and quercetin inhibitory activity against enzymes had synergistic effects of the TBS digestion.

Effect of Roasting on the Antioxidant Activity, Phenolic Composition, and Nutritional Quality of Pumpkin (Cucurbita pepo L.) Seeds

In recent years, with the increasing awareness of health concerns and environment protection needs, there is a growing interest for consumers to choose plant-based food diets compared with those made from animal origin. Pumpkin seed is an excellent dietary source for protein, oil, and some essential micronutrients. Raw pumpkin seed may have a compromised flavor, color, as well as digestibility. Therefore, the objective of present study is to study the influence of roasting (120, 160, and 200°C for 10 min) on the phenolics content, flavonoids content, antioxidant property, fatty acids, and volatile matter composition, as well as protein profile of pumpkin seeds. Our results indicated that, total phenolic compounds, total flavonoids content, as a consequence, total antioxidant capacity increased as the roasting temperature increased. Maillard reaction products and lipid peroxidation products were identified, especially from those pumpkin seeds roasted at high temperature. In the meantime, the composition and content of fatty acids did not change significantly after roasting. The results of electrophoresis and particle size analysis showed that the optimum roasting temperature was 160°C to obtain protein with better nutritional quality. The findings of this study may contribute to the utilization of pumpkin seed component in plant-based diets with increased nutritional quality.

Maillard Reaction Products in Gluten-Free Bread Made from Raw and Roasted Buckwheat Flour

The formation of Maillard reaction products (MRPs) in gluten-free bread made from roasted and raw buckwheat flour was examined. The levels of phenolic compounds such as flavonoids (catechin, naringenin, quercetin, rutin, and others) and phenolic acids (like 4-hydroxybenzoic, caffeic, dihydroxybenzoic, ferulic, gallic, syringic, vanillic, and p-coumaric) were measured using reversed-phase ultra-high performance liquid chromatography-electrospray ionization mass spectrometry (RP–UHPLC–ESI-MS). Early and advanced Maillard reaction products were analyzed using HPLC, whereas spectrofluorimetric analysis was used to determine the levels of fluorescent intermediate compounds (FIC). The total levels of phenolic compounds were higher in the case of buckwheat bread prepared from roasted buckwheat flour (156 and 140 µg/g of crumb and crust, respectively). Rutin, gallic acid, and catechin were the most abundant phenolic compounds detected in roasted buckwheat bread. The roasting process resulted in significantly lower radical scavenging capacities (ABTS) of the total phenolics and flavonoids in the buckwheat bread. Taking into consideration these Maillard reaction products, we observed a significant increase in FIC level in roasted buckwheat crumb and crust (at about 40%, and 38%, respectively). At the same time, the Nε-(carboxymethyl)lysine (CML) level did not change in roasted or raw buckwheat bread crumb, though in roasted buckwheat crust the concentration of CML increased by about 21%.

An overview of conventional and emerging techniques of roasting: Effect on food bioactive signatures

Roasting is a food processingtechnique that employs the principle of heating to cook the product evenly and enhance the digestibility, palatability and sensory aspects of foods with desirable structural modifications of the food matrix. With the burgeoning demand for fortified roasted products along with the concern for food hygiene and the effects of harmful compounds, novel roasting techniques, and equipment to overcome the limitations of conventional operations are indispensable. Roasting techniques employing microwave, infrared hot-air, superheated steam, Revtech roaster, and Forced Convection Continuous Tumble (FCCT) roasting have been figuratively emerging to prominence for effectively roasting different foods without compromising the nutritional quality. The present review critically appraises various conventional and emerging roasting techniques, their advantages and limitations, and their effect on different food matrix components, functional properties, structural attributes, and sensory aspects for a wide range of products. It was seen that thermal processing at high temperatures for increased durations affected both the physicochemical and structural properties of food. Nevertheless, novel techniques caused minimum destructive impacts as compared to the traditional processes. However, further studies applying novel roasting techniques with a wide range of operating conditions on different types of products are crucial to establish the potential of these techniques in obtaining safe, quality foods.

Black rice (Oryza sativa L.) processing: Evaluation of physicochemical properties, in vitro starch digestibility, and phenolic functions linked to type 2 diabetes

Black rice is recognized for managing diabetes in Chinese folk medicine. Therefore, the present study investigates the effect of thermal treatments and the succeeding cooking on black rice physicochemical properties, phenolic composition, total antioxidant activity (TAA), enzymes and glycation inhibition in addition to starch digestibility. Thermal decomposition of anthocyanin and cyanidin-3-glucoside was evident across all processing methods and reflected in increasing levels of protocatechuic acid, while proanthocyanidins (TPAC) were susceptible to cooking. Roasting of grains sustained total phenolics (TPC), flavonoids (TFC), TPAC, and antilipase activity. Additionally, the combined effect of frying and cooking diminished TFC, TPAC, and α-glucosidase inhibition. The thermally treated grains showed pronounced activity against α-amylase, α-glucosidase, and glycation, whereas their cooked counterparts reduced the estimated glycemic index (eGI), and enhanced resistant starch (RS). Processed grains chrominance, TAA, and apparent amylose content (AAC) showed a significant correlation with phenolics. These findings are demonstrating that black rice processing is favorable for the dietary management of metabolic disorders such as diabetes and hyperlipidemia.

Effects of "nine steaming nine sun-drying" on proximate composition, oil properties and volatile compounds of black sesame seeds

Black sesame seeds (BSS) were processed by nine cycles of steaming and sun-drying, and the chemistry of their resulting products studied. That is, the shell color and structure, proximate composition, oil properties and volatile compounds of raw BSS were determined and compared with processed BSS. Various levels of shell color change and structure damage were observed. The proximate composition also differed, whereas the relative proportion of fatty acids and oil properties were unchanged. SPME-GCMS analysis revealed that aldehydes, hydrocarbons and alcohols were the main volatile compounds. And compared with raw BSS, four volatile substances were newly detected in the processed BSS. Principal component analysis (PCA) displayed the overall difference between samples and showed that repeated steaming and sun-drying process had a significant impact on the chemical composition of BSS.

Effect of growing conditions on proximate, mineral, amino acid, phenolic composition and antioxidant properties of wheatgrass from different wheat (Triticum aestivum L.) varieties

Wheatgrass juice powder (WJP) from four wheat varieties grown using soil, coco-peat with nutrient solution (CNS) and water (soaked (8 h), germinated (36 h) and harvested on 10th day) were examined for proximate composition, mineral, amino acid, phenolic (free and bound) composition and antioxidant properties. The yield, ash and protein contents of WJP ranged between 4.88-7.87%, 5.18-15.93% and 38.75-50.17%, respectively. The total phenolic, flavonoid, chlorophyll content (TCC) and antioxidant activity varied from 12.02 to 17.44 mg GAE/g, 4.38-10.10 mg QE/g, 3.01-5.63 mg/g, and 13.54-17.33 μmol TE/g, respectively. HD-3086 grown using soil exhibited highest antioxidant properties, TCC and Mg content. WJP of C-306 grown using CNS had abundant essential amino acids (AAs). Phenolic acids (ferulic, syringic and sinapic acids) and flavonoids (catechin, rutin, vitexin and isovitexin) and minerals (K, P, Ca, Mg, Na and Fe) were predominant in WJP. The AAs and free phenolics were more in CNS and soil grown WJP, respectively.

Application of Infrared Heating for Roasting Nuts

Roasting is a key process in production of nuts. Improving the flavor and crispiness of texture in nuts is considered as a purpose of roasting, which increases the overall acceptance of the product. This review aims to introduce the infrared method as a new technique of roasting and evaluate the quality characteristics of some nuts after infrared roasting. Usually, the traditional roasting methods are time-consuming with high energy consumption and low production efficiency. One of the best ways to decrease roasting time and energy consumption is to provide heat by infrared (IR) radiation. However, the low penetration power of infrared radiation is one of the limitations of this method. The combination of infrared with other thermal methods can overcome this limitation. Studies have been done on roasting of nuts and other foods by different IR roasting methods such as IR, IR-hot air, and IR-microwave roasting methods. This paper reviews the effect of different IR roasting methods on the quality characteristics of roasted pistachio, peanut, hazelnut, almond, sunflower, soybean, and other food products. IR heating has been applied successfully to the roasting of some nuts. The use of infrared roasting has several advantages in comparison with traditional convective roasting methods. According to the results of most of these studies, the combination of infrared with other thermal methods to roast nuts has distinctly improved the potential of the technology as compared to the IR roasting alone.