Antioxidant Activities of Different Peanut (Arachis hypogaea L.) Market Types by Spectrophotometric Techniques Combined with Chemometrics

Peanut is rich in oil and protein and has a large content of bioactive constituents consisting of tocopherols, phytosterols, and so on. Generally, Virginia, Spanish, Valencia and Runner market types are grown of peanut. In this study, it is aimed to determine the antioxidant activity, total phenolic content and total flavonoid content of peanuts from four different market types, for the first time, and group them with principal component analysis (PCA) and hierarchical cluster analysis (HCA). For PCA, PC1 and PC2 explained 87.655 % of the total variation and, according to the HCA of peanut samples, two main groups were determined. The total phenolic content changed 1.556 to 2.899 mg GAE/g. The lowest value have seen at Spanish merket type to determine the antioxidant activities of peanut samples were maked FRAP and DPPH assay, the lowest FRAP value (8.136 μmol FeSO47H2O/g sample) was seen at Valencia market type, the highest (14.004 μmol FeSO47H2O/g sample) was seen at Virginia market type. It was determined that the total flavonoid, total phenolic content, and antioxidant activities of the Virginia, Valencia, Spanish, and Runner market types included in the study were different from each other, and the Virginia market type showed superior characteristics compared to the others. The results obtained suggest that Virginia market type may be preferred more especially in peanut cultivation for food uses. It is thought that this study can be a source for future studies by eliminating a deficiency in the literature.

Immobilizing white-rot fungi laccase: Toward bio-derived supports as a circular economy approach in organochlorine removal

Despite their high persistence in the environment, organochlorines (OC) are widely used in the pharmaceutical industry, in plastics, and in the manufacture of pesticides, among other applications. These compounds and the byproducts of their decomposition deserve attention and efficient proposals for their treatment. Among sustainable alternatives, the use of ligninolytic enzymes (LEs) from fungi stands out, as these molecules can catalyze the transformation of a wide range of pollutants. Among LEs, laccases (Lac) are known for their efficiency as biocatalysts in the conversion of organic pollutants. Their application in biotechnological processes is possible, but the enzymes are often unstable and difficult to recover after use, driving up costs. Immobilization of enzymes on a matrix (support or solid carrier) allows recovery and stabilization of this catalytic capacity. Agricultural residual biomass is a passive environmental asset. Although underestimated and still treated as an undesirable component, residual biomass can be used as a low-cost adsorbent and as a support for the immobilization of enzymes. In this review, the adsorption capacity and immobilization of fungal Lac on supports made from residual biomass, including compounds such as biochar, for the removal of OC compounds are analyzed and compared with the use of synthetic supports. A qualitative and quantitative comparison of the reported results was made. In this context, the use of peanut shells is highlighted in view of the increasing peanut production worldwide. The linkage of methods with circular economy approaches that can be applied in practice is discussed.

Effect of Electron-Beam Irradiation on Functional Compounds and Biological Activities in Peanut Shells

Peanut shells, rich in antioxidants, remain underutilized due to limited research. The present study investigated the changes in the functional compound content and skin aging-related enzyme inhibitory activities of peanut shells by electron-beam treatment with different sample states and irradiation doses. In addition, phenolic compounds in the peanut shells were identified and quantified using ultra-performance liquid chromatography with ion mobility mass spectrometry-quadrupole time-of-flight and high-performance liquid chromatography with a photodiode array detector, respectively. Total phenolic compound content in solid treatment gradually increased from 110.31 to 189.03 mg gallic acid equivalent/g as the irradiation dose increased. Additionally, electron-beam irradiation significantly increased 5,7-dihydroxychrome, eriodictyol, and luteolin content in the solid treatment compared to the control. However, liquid treatment was less effective in terms of functional compound content compared to the solid treatment. The enhanced functional compound content in the solid treatment clearly augmented the antioxidant activity of the peanut shells irradiated with an electron-beam. Similarly, electron-beam irradiation substantially increased collagenase and elastase inhibitory activities in the solid treatment. Mutagenicity assay confirmed the stability of toxicity associated with the electron-beam irradiation. In conclusion, electron-beam-irradiated peanut shells could serve as an important by-product with potential applications in functional cosmetic materials.

Evaluation of Roasting and Grilling Effects on Chemical Composition, Volatile Profiles, and Toxicity of Stink Bugs (Tessaratoma papillosa): Implications for Utilization as Functional Food Ingredients

The stink bug (Tessaratoma papillosa) is a highly popular edible insect in Thai traditional cuisine, but little research has investigated the effects of heat treatment on the quality of stink bugs. Therefore, we aimed to evaluate the effects of roasting and grilling on the chemical changes and volatile compounds of late nymph and adult stink bugs. In general, all treated samples showed increases in phenolic acid, tocopherols, and amino acid contents and a decrease in the content of fiber compared with raw stink bugs (p < 0.05). Cinnamic acid significantly increased by over 200% in late nymph insects and 30% in adult insects after roasting, whereas syringic acid decreased after cooking (p < 0.05). The most predominant volatile compound found in all samples was 5-methyl-octadecane and it decreased after cooking, while volatile alkane compounds increased after cooking. The processed sample extracts showed higher toxicity on oral cancer KB and cervical cancer Hela cells than on Vero cells. We have demonstrated that different cooking methods affected the chemical components which may result in quality attributes if stink bug is to be used as a functional ingredient/food. It may be helpful to improve the nutritional and functional values of stink bugs during deep processing.

Comprehensive review of composition distribution and advances in profiling of phenolic compounds in oilseeds

A wide range of phenolic compounds participate in oilseed growth, regulate oxidative stability of corresponding vegetable oil, and serve as important minor food components with health-promoting effects. Composition distribution of phenolic compounds varied in oilseeds. Isoflavones, sinapic acid derivatives, catechin and epicatechin, phenolic alcohols, chlorogenic acid, and lignans were the main phenolic compounds in soybean, rapeseed, peanut skin, olive, sunflower seed, sesame and flaxseed, respectively. Among which, the total isoflavones content in soybean seeds reached from 1,431 to 2,130 mg/100 g; the main phenolic compound in rapeseed was sinapine, representing 70–90%; chlorogenic acid as the predominant phenolic compound in sunflower kernels, represented around 77% of the total phenolic content. With the rapid development of analytical techniques, it is becoming possible for the comprehensive profiling of these phenolic compounds from oilseeds. This review aims to provide recently developments about the composition distribution of phenolic compounds in common oilseeds, advanced technologies for profiling of phenolic compounds by the metabolomics approaches based on mass spectrometry. As there is still limited research focused on the comprehensive extraction and determination of phenolics with different bound-forms, future efforts should take into account the non-targeted, pseudo-targeted, and spatial metabolomic profiling of phenolic compounds, and the construction of phenolic compound database for identifying and quantifying new types of phenolic compounds in oilseeds and their derived products.

Effect of processing on the antioxidant activities of porridges and Pittu prepared from finger millets (Eleusine coracana)

Finger millets are important coarse grains that exhibit high levels of phenolic compounds and antioxidant activities among other cereals. Grains are subjected to a number of thermal treatments and this could affect the contents and bioactivities of phenolic compounds. The aim of the present study was to determine the phenolic contents and antioxidant activities of finger millet flour and foods, namely porridges and Pittu subjected to several thermal treatments such as roasting, parboiling, and parboiled roasting of flour and open boiling and steaming of foods prepared using flour. The effect of the addition of spices on phenolic content and antioxidant activities to open boiled foods was determined. Antioxidant activities of phenolic extracts obtained from finger millet flour and foods were studied for their total phenolic, flavonoids and proanthocyanidins contents, radical scavenging capacities, reducing power, ferrous ion chelating capacity, and antioxidant activity in a β-carotene/linoleate emulsion. The roasted flour and foods had higher total phenolic content (TPC) than other counterparts and ranged from 21.58 to 28.63 µmol ferulic acid equivalents/g dry matter. All flour and food preparations exhibited effective inhibition of radicals, reducing power, ferrous ion chelating activity, and antioxidant activity in the β-carotene/linoleate emulsion and the degree of activity depended on the processing conditions adopted in food preparations.

Foods prepared using steaming showed lower phenolic content and antioxidant activities in general than those of open-boiled counterparts. The addition of spices, namely garlic and cinnamon improved the phenolic contents and antioxidant activities of open-boiled porridges. The knowledge generated from this study may help to exploit the use of finger millets as a functional food ingredient to promote health and wellness.

Graphical abstract