Daily Consumption of Oregon Hazelnuts Affects α-Tocopherol Status in Healthy Older Adults: A Pre-Post Intervention Study.
Nuts and Cardio-Metabolic Disease: A Review of Meta-Analyses.
Walnut Consumption for Two Years and Leukocyte Telomere Attrition in Mediterranean Elders: Results of a Randomized Controlled Trial.
Microwave Use in the Control of Ephestia kuehniella (Lepidoptera: Pyralidae) in Dried Fig and Raisin and Effects on Fruit Sensory Characteristics.
Microwave heating is an environmentally friendly method for killing pest insects and here its efficacy in the control of a pest species of dried fig and raisin was assessed. Dried fig and raisin samples were infested with Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) larvae and heated in a microwave oven at power outputs of 450, 720, and 900 W for 20, 30, 40, and 50 s. Following exposure to the microwave treatments, larval mortality and changes to organoleptic properties, which indicate consumer preference and include aroma, color, sweetness, acerbity, fragility, stiffness, and overall acceptability, were assessed. Our results showed mortality rates were greatest with the highest degree and duration of microwave exposure, where 100% mortality was recorded at 900 W with an exposure time of 50 s. The sensory evaluations of the fruit showed that microwave heating had some effect on aroma, color, fragility, sweetness, and overall acceptability, but no effect on acerbity and stiffness in dried fig, whereas in raisin, there were no impacts on acerbity, stiffness, or sweetness, but aroma, color, fragility, and overall acceptability were affected. We conclude that application of lower intensities of microwave treatment may provide acceptable levels of pest control in stored dried fruit without an associated trade-off in the reduction in quality of sensory attributes.
A comprehensive review of the value-added uses of peanut (Arachis hypogaea) skins and by-products.
Globally, peanut seeds are grown for oil production, peanut butter, confections, snacks and protein extenders, leaving the peanut by-products (skins, peanut hulls) as waste for disposal. Numerous studies have identified the value added attributes of peanut skins and/or peanut skin extracts as an antioxidant, functional food ingredient, animal production feed ingredient, and antimicrobial agent. This manuscript presents a comprehensive review of the food and non-food uses of peanut skins and/or extracts, and new uses of this significant agricultural waste product produced in the peanut industry. An improved comprehensive knowledge and better understanding of the value added uses of peanut skins enables us to better define future food and non-food uses of this agricultural by-product.
RNA-Seq Reveals Flavonoid Biosynthesis-related Genes in Pecan (Carya illinoinensis) Kernels.
Pecan (Carya illinoinensis) is an important nut tree in the world. The high concentration of flavonoid in its kernels makes it an excellent healthy food. However, the molecular basis of flavonoid biosynthesis in pecan remains unclear, which hinders quality breeding in this plant. Therefore, in order to obtain crucial genes involved in flavonoid biosynthesis, the changes in flavonoid profiles and the transcriptomes of four development stages (late water, gel, dough and mature stages) of kernels were analyzed. As a result, the highest levels of total phenolic, condensed tannin and flavan-3-ols were observed at the "late water stage". Catechin was the most abundant flavan-3-ol at different development stages. In total, 64,773 unigenes were obtained, and 46,924 (72.44%) unigenes were annotated. After differentially expressed gene (DEG) analysis, 12,750 unique DEGs were identified. Flavonoid-related DEGs of 36 structural genes and 8 MYBs were obtained. The structural gene set contained 3 PALs, 3 CHSs, 2 CHIs, an F3H, 2 F3'Hs, 2 F3'5'Hs, 1 DFR, 1 ANS, 2 LARs and 2 ANRs. The expression patterns of most of the structural genes were consistent with the changes in flavonoid profiles during kernel development. We believe that this RNA-Seq dataset will provide valuable resources for unraveling the molecular mechanism of flavonoid metabolism in pecan and will significantly promote the genetic study and quality breeding in this plant.
A Quantitative Risk Assessment of Human Salmonellosis from Consumption of Walnuts in the United States.
We assessed the risk of human salmonellosis from consumption of shelled walnuts in the United States and the impact of 0- to 5-log reduction treatments for Salmonella during processing. We established a baseline model with Salmonella contamination data from 2010 to 2013 surveys of walnuts from California operations to estimate baseline prevalence and levels of Salmonella during preshelling storage and typical walnut processing stages, considered U.S. consumption data, and applied an adapted dose-response model from the Food and Agriculture Organization and the World Health Organization to evaluate risk of illness per serving and per year. Our baseline model predicted 1 case of salmonellosis per 100 million servings (95% confidence interval [CI], 1 case per 3 million to 1 case per 2 billion servings) of walnuts untreated during processing and uncooked by consumers, resulting in an estimated 6 cases of salmonellosis per year (95% CI, <1 to 278 cases) in the United States. A minimum 3-log reduction treatment for Salmonella during processing of walnuts eaten alone or as an uncooked ingredient resulted in a mean risk of <1 case per year. We modeled the impact on risk per serving of three atypical situations in which the Salmonella levels were increased by 0.5 to 1.5 log CFU per unit pretreatment during processing at the float tank or during preshelling storage or posttreatment during partitioning into consumer packages. No change in risk was associated with the small increase in levels of Salmonella at the float tank, whereas an increase in risk was estimated for each of the other two atypical events. In a fourth scenario, we estimated the risk per serving associated with consumption of walnuts with Salmonella prevalence and levels from a 2014 to 2015 U.S. retail survey. Risk per serving estimates were two orders of magnitude larger than those of the baseline model without treatment. Further research is needed to determine whether this finding reflects variability in Salmonella contamination across the supply or a rare event affecting a portion of the supply.
Effect of Roasting and Storage on the Formation of Maillard Reaction and Sugar Degradation Products in Hazelnuts (Corylus avellana L.).
This study investigated the effect of roasting (150°C for 30 min) and storage (12 months at 4°C, 25°C and 25°C in vacuum package), conditions of which are generally applied in the industry and markets, on the formation of Maillard reaction and sugar degradation products, namely dicarbonyl compounds, 5-hydroxymethylfurfural, N-e-fructosyllysine, and N-e-carboxymethyllysine in Tombul and Levant hazelnuts. Roasting increased all dicarbonyl compounds significantly (p<0.05). The concentration of methylglyoxal was highest while 1-deoxyglucosone was lowest in roasted hazelnuts. 5-hydroxymethylfurfural and N-e-carboxymethyllysine also increased significantly (p<0.05) with roasting while furosine decreased. Roasting changed the progress of Maillard reaction from the early stage to the advanced stage. On the other hand, there were no significant changes (p>0.5) in the concentration of Maillard reaction and sugar degradation products independent of the storage conditions or time and hazelnut variety, except for glyoxal, diacetyl, and 1-deoxyglucosone. Therefore, neither 5-hydroxymethylfurfural nor furosine could be suggested as the storage marker of Maillard reaction and sugar degradation.
A review on the application of vibrational spectroscopy to the chemistry of nuts.
Nuts are highly appreciated due to their nutritional relevance and flavour, being the source of many desirable and healthy compounds as polyunsaturated fatty acids and antioxidants. Their characterization became the target of many studies in the last years through conventional analytical techniques as chromatographic ones. Due to the limitations associated to these techniques, as time, cost and environmental concerns, spectroscopic techniques have been increasingly pointed as reliable alternatives. Either applied to raw materials quality control or to more complex process, as industrial in-line monitoring, spectroscopic techniques, namely vibrational spectroscopy, are gathering strong acceptance. This paper presents a review on the application of vibrational spectroscopy, infrared and Raman, to nuts characterization. Estimates of several qualitative and quantitative parameters, origin authentication and/or adulteration in almonds, peanuts, pine nuts, hazelnuts, walnuts, Brazil nuts, cashews, chestnuts and pistachios will be covered. Advantages and limitations of these techniques and future trends will also be discussed.
Comparison of amygdalin and benzaldehyde levels in California almond (Prunus dulcis) varietals.
Almonds (Prunus dulcis), are characterized into three flavor phenotypes: bitter, semi-bitter and sweet. Amygdalin is a cyanogenic diglucoside responsible for bitterness in almonds. Studies have shown that amygdalin can hydrolyze to release benzaldehyde, which is the key component of almond aroma. In this study, the amygdalin and benzaldehyde content of fourteen sweet cultivars of almonds from four growing regions in California were determined. Solid-phase extraction and ultra high-pressure liquid chromatography coupled with electrospray triple-quadrupole mass spectrometry (UHPLC-(ESI)MS/MS) were used to determine the amygdalin content in the raw almond kernels. Headspace solid phase microextraction (HS-SPME) coupled with a gas chromatography mass spectrometry (GC/MS) was used to determine the benzaldehyde concentration in raw almond kernels. Saturated salt water was added to the sample to improve the extraction of benzaldehyde in the headspace. Results indicated that the mean concentration of both amygdalin and benzaldehyde are significantly different (p<0.0001) among the fourteen cultivar. Furthermore, a positive correlation was found between the amygdalin and benzaldehyde concentrations among the 14 cultivars. Although 'Nonpareil' cultivars is considered the premier snacking almond, 'Aldrich' has significantly higher concentrations of benzaldehyde in the headspace, the key contributor of the almond aroma.