Chemical Changes and Oxidative Stability of Peanuts as Affected by the Dry-Blanching

Wheat and Rice beyond Phenolic Acids: Genetics, Identification Database, Antioxidant Properties, and Potential Health Effects

Wheat and rice play a vital role in human nutrition and food security. A better understanding of the potential health benefits associated with consuming these cereals, combined with studies by plant scientists and food chemists to view the entire food value chain from the field, pre and post-harvest processing, and subsequent "fork" consumption, may provide the necessary tools to optimize wheat and rice production towards the goal of better human health improvement and food security, providing tools to better adapt to the challenges associated with climate change. Since the available literature usually focuses on only one food chain segment, this narrative review was designed to address the identities and concentration of phenolics of these cereal crops from a farm-to-fork perspective. Wheat and rice genetics, phenolic databases, antioxidant properties, and potential health effects are summarized. These cereals contain much more than phenolic acids, having significant concentrations of flavonoids (including anthocyanins) and proanthocyanidins in a cultivar-dependent manner. Their potential health benefits in vitro have been extensively studied. According to a number of in vivo studies, consumption of whole wheat, wheat bran, whole rice, and rice bran may be strategies to improve health. Likewise, anthocyanin-rich cultivars have shown to be very promising as functional foods.

Vitamin E as an essential micronutrient for human health: Common, novel, and unexplored dietary sources

Vitamin E comprises a group of vitamers that includes tocopherols and tocotrienols. They occur in four homologues according to the number and position of methyl groups attached to the chromanol ring. Vitamin E, a liposoluble antioxidant, may participate as an adjuvant in the prevention and treatment of cardiovascular, neurological, and aging-related diseases. Furthermore, vitamin E has applications in the food industry as a natural additive. In this contribution, the most recent information on the dietary sources of vitamin E, including common, novel, and unexplored sources, is presented. Common edible oils, such as those of corn, olive, palm, rice bran, and peanut, represent the most prominent sources of vitamin E. However, specialty and underutilized oils such as those obtained from tree nuts, fruit seeds, and by-products, emerge as novel sources of this important micronutrient. Complementary studies should examine the tocotrienol content of vitamin E dietary sources to better understand the different biological functions of these vitamers.

Volatile Profile of Nuts, Key Odorants and Analytical Methods for Quantification

The presence of nuts in diets has notably increased due to their composition, and the presence of antioxidants and their unsaturated fatty acid profile has led to a considerable increase in their consumption. The volatile profile of nuts is important from different points of view. It affects consumer’s selection, influences raw material selection for the production of composite foods, dictates variety selection in breeding programs, and, from a quality perspective, its changes can indicate food degradation or alteration. A review of the published bibliography concerning the determination of volatiles in nuts has been carried out. The information retrieved has been divided into four main sections. First, a discussion on the main volatiles present in nuts is performed; next, a revision of the methods used to determine the volatiles is presented; and, finally, two sections describing how harvesting conditions, healthy state and the thermal treatment of nuts modifies their volatile profile are added. Analysis of the published bibliography denoted the complexity of volatile determination and the different variables that can modify the compounds present in the volatile fraction of nuts.

Extraction Technology Can Impose Influences on Peanut Oil Functional Quality: A Study to Investigate the Lipid Metabolism by Sprague-Dawley Rat Model

In this study, peanut oil was prepared by cold pressing (temperature under 60 °C), hot pressing (temperature above 105 °C), and enzyme-assisted aqueous extraction technology. Influences of an extraction technology on the oil fatty acid composition and the content of minor bioactive compounds, including tocopherols, polyphenols, and squalene, were investigated in detail. High-fat-diet Sprague-Dawley (SD) rat model was then established to probe the impact of cold-pressed peanut oil (CPO), hot-pressed peanut oil (HPO), and enzyme-assisted aqueous-extracted peanut oil (EAO) on lipid metabolism outcomes, to explore influences of different extraction technologies on lipid functional quality. Results showed that oleic acid was the predominate fatty acid in the EAO (52.57 ± 0.11%), which was also significantly higher (P < 0.05) than CPO and HPO. The HPO showed higher total tocopherol and polyphenol contents (206.84 ± 6.93 mg/kg and 47.87 ± 6.50 mg GA/kg, respectively) than CPO and EAO (P < 0.05). However, the squalene content in CPO was 475.47 ± 12.75 mg/kg, which was the highest among the three oils (P < 0.05). The animal experiment results revealed that EAO could be more prone to induce lipid accumulation in the liver, which may likely to cause nonalcoholic fatty liver disease. However, the serum lipid profiles indicated that the CPO was more beneficial than the EAO and HPO in lowering the serum low-density lipoprotein cholesterol, alanine aminotransferase, and aspartate aminotransferase contents, and increasing the high-density lipoprotein cholesterol content. All of our efforts indicated that an extraction technology can affect the peanut oil lipid fatty acid composition, the bioactive compounds content, and, correspondingly, the lipid metabolism in SD rats.

Date palm wood as a new source of phenolic antioxidants and in preparation of smoked salmon

The potential of date palm wood (DPW) as a new source of phenolic antioxidants was investigated in this contribution. The total phenolic content and antiradical activity of soluble and insoluble-bound fractions of DPW was compared to those of maple wood (MW). Furthermore, salmon was smoked with DPW and MW. Irrespective of the wood type, volatile phenolic compounds were mainly methoxyphenols, with the highest contribution from eugenol followed by guaiacol and their corresponding derivatives, as evaluated by solid-phase microextraction and gas chromatography-mass spectrometry. Salmon smoked with DPW showed a higher oxidative stability than that of MW during 21 days of storage at 4°C, which was explained by the higher content of volatile phenolic compounds in the smoke generated from DPW. Minor differences were detected for the instrumental color between both samples of smoked salmon. Therefore, smoking with DPW may be used for industrial meat and fish smoking purposes. PRACTICAL APPLICATIONS: Smoking has long been used to preserve fish and meat products. The process changes the appearance and gives a desirable flavor to the product. However, high temperatures applied during smoking may also induce lipid oxidation, the extent of which is counterbalanced by the antioxidant action of phenolics in woodsmoke. In this sense, the desired interactions of the smoke volatiles in the food matrix dictates the quality of the final product. Volatile phenolics released upon smoking are dependent on the type of wood. Thus, use of a specific wood might provide unique products, hence date palm wood (DPW) used in this work may not only provide special smoked fish products but its use could be extended to other smoked products. Hence, this contribution extends the possible feedstocks for the preparation of smoked products.

Oxidative Stability of Selected Edible Oils

The aim of the study was to examine and compare oxidative stability of refined (peanut, corn, rice bran, grapeseed, and rapeseed) oils. The oils were subject a Schaal Oven Test (temperature 63 ± 1 °C) and a Rancimat test (temperature 120 °C) and their stability was compared at the 1st and 12th month of storage. Changes in the peroxide (PV) and anisidine (AnV) values in the thermostat test were the fastest in rapeseed oil and grapeseed oil. The best quality was preserved by peanut and corn oils both in the first and the twelfth month of storage. The induction times for the rice bran, corn, peanut, and rapeseed oils were similar from 4.77 h to 5.02 h in the first month and from 3.22 h to 3.77 h in the twelfth month. The shortest induction times were determined for grapeseed oil: 2.4 h and 1.6 h, respectively. A decrease of oxidative stability of about 30% was found in all the oils after 12 months of storage. The PV of 10, determined in the thermostat and Rancimat tests, were achieved at the latest in corn oil and the fastest in rice bran oil.

Tocopherols and Tocotrienols in Common and Emerging Dietary Sources: Occurrence, Applications, and Health Benefits

Edible oils are the major natural dietary sources of tocopherols and tocotrienols, collectively known as tocols. Plant foods with low lipid content usually have negligible quantities of tocols. However, seeds and other plant food processing by-products may serve as alternative sources of edible oils with considerable contents of tocopherols and tocotrienols. Tocopherols are among the most important lipid-soluble antioxidants in food as well as in human and animal tissues. Tocopherols are found in lipid-rich regions of cells (e.g., mitochondrial membranes), fat depots, and lipoproteins such as low-density lipoprotein cholesterol. Their health benefits may also be explained by regulation of gene expression, signal transduction, and modulation of cell functions. Potential health benefits of tocols include prevention of certain types of cancer, heart disease, and other chronic ailments. Although deficiencies of tocopherol are uncommon, a continuous intake from common and novel dietary sources of tocopherols and tocotrienols is advantageous. Thus, this contribution will focus on the relevant literature on common and emerging edible oils as a source of tocols. Potential application and health effects as well as the impact of new cultivars as sources of edible oils and their processing discards are presented. Future trends and drawbacks are also briefly covered.