Preferences for groundnut products among urban residents in Ghana.

BACKGROUND: The present study identifies factors influencing preferences for common groundnut products using information about product perceptions from residents in Ghana's cities collected in 2011. In Ghana, domestically produced groundnuts, processed into a variety of groundnut products, are a vital source of protein and other nutrients. RESULTS: Response summaries provide insights about the eating frequency of various products, whereas a bivariate ordered probit model identifies factors influencing preferences for groundnut paste and roasted groundnuts. Attributes such as taste, protein content and healthfulness are important for roasted groundnuts, whereas aroma, taste and protein content are associated with a preference for groundnut paste. Large households prefer paste, whereas the less educated and those from households with children prefer roasted groundnuts. Adding a child (4-12 years old) increases probability of 'liking very much' roasted groundnuts and an additional adult at home changes that probability regarding groundnut paste. College-educated consumers prefer groundnut paste less than those with less education. Consumers from Tamale and Takoradi prefer roasted groundnuts and groundnut paste more than Accra households. CONCLUSIONS: Taste and protein content are attributes of groundnut paste and roasted groundnuts preferred by consumers. Location is a significant factor shaping preference for roasted groundnuts and groundnut paste. © 2017 Society of Chemical Industry.

Resveratrol in peanuts.

Peanuts are important dietary food source of resveratrol with potent antioxidant properties implicated in reducing risk of cancer, cardiovascular and Alzheimer's disease, and delaying aging. Resveratrol is a naturally occurring stilbene phytoalexin phenolic compound produced in response to a variety of biotic and abiotic stresses. This paper is a review of trans-resveratrol and related stilbenes from peanuts--their chemical structures, mechanisms for their biosynthesis, and concentrations in comparison with other major food sources. It will also discuss trans-resveratrol's absorption, bioavailability, and major health benefits; processes to enhance their biosynthesis in peanuts by biotic and abiotic stresses; process optimization for enhanced levels in peanuts and their potential food applications; and methods used for its extraction and analysis.

Effect of ultraviolet doses in combined ultraviolet-ultrasound treatments on trans-resveratrol and trans-piceid contents in sliced peanut kernels.

Peanuts are known to synthesize resveratrol, a stilbene phytoalexin, associated with cancer chemopreventive activity and cardioprotection. A modified HPLC method developed and validated to determine trans-resveratrol and trans-piceid concentrations in a single analysis run exhibited recoveries, precision, linearity, and limits of detection consistent with or better than those of methods previously reported in the literature. The effect of combined treatments, ultrasound (US) followed by varying UV light (UV) doses (three distances, three exposure times) on trans-resveratrol and trans-piceid concentrations in peanuts was determined. All nine US-UV treatments significantly increased trans-resveratrol contents from 0.03 microg/g, in untreated peanut control, to 2.10-4.73 microg/g and trans-piceid contents from 0.07 to 0.23-0.38 microg/g. Increases in trans-resveratrol were not influenced by UV distance and time. US and UV, individually, increased trans-resveratrol to 4.29 and 2.36 microg/g, respectively. The US and UV treatment combinations used did not exhibit synergistic effect compared to US treatments alone.

Elicitation of resveratrol in peanut kernels by application of abiotic stresses.

Application of no postharvest stress or by size reduction, grinding, chopping, or slicing and exposure to UV light or ultrasound were investigated for the elicitation of trans-resveratrol, total phenolic compounds, and antioxidant activity (AOA) in peanut kernels. AOA and total phenolic compounds did not increase in stressed peanuts over incubation times 0-48 h at 25 degrees C; however, an increase in trans-resveratrol concentration over time occurred. Slicing (2 mm), ultrasound exposure for 4 min at 25 degrees C, and incubation for 36 h produced the highest level of trans-resveratrol synthesis in peanuts, increasing concentrations from 0.48 +/- 0.08 microg/g in untreated peanuts to 3.96 +/- 0.96 microg/g. AOA in stressed peanuts was negatively correlated with trans-resveratrol concentration, indicating that as AOA decreased trans-resveratrol concentration increased.

Physicochemical and sensory characteristic changes in fortified peanut spreads after 3 months of storage at different temperatures.

Three amino acid-balanced, vitamin- and mineral-fortified peanut spreads were stored at 4, 23, and 40 degrees C for 3 months. These were 69.6% peanut/19% soybean-40.5% fat, 61.9% peanut/19% soybean-44.5% fat, and 74.1% peanut/14% nonfat dry milk (NFDM)-40% fat. The peanut spreads were fortified with vitamin A, thiamin, riboflavin, vitamin B(6), vitamin C, calcium, and iron to provide 33.3% of the Recommended Dietary Allowances for children. Water-soluble vitamins were quite stable in deaerated peanut spreads. The antioxidant activity of phytochemicals in soybean prevented vitamin A degradation in soy-containing spreads, whereas the NFDM spread lost 70% of the initial content. Instron analysis detected major changes in texture when peanut spreads were stored at 40 degrees C, suggesting that the polymorphic form of lipid transformed and the proper crystallization of stabilizer was destroyed. Panelists did not detect the texture changes in peanut spreads stored at different temperatures. At 40 degrees C, the primary deteriorative changes in sensory quality were increased browning and the development of "soybean" and "oxidized" flavors as well as decreased "roasted peanutty" flavor.