Ribeiro, S.R., B. Klein, Q.M. Ribeiro, I.D. Dos Santos, A.L. Gomes Genro, D. de Freitas Ferreira, J.J. Hamann, J.S. Barin, A.J. Cichoski, D. Fronza, V. Both, R. Wagner, 2020. Chemical composition and oxidative stability of eleven pecan cultivars produced in southern Brazil. Food Res Int. 136:109596. doi: 10.1016/j.foodres.2020.109596.
Nuts are considered highly nutritious foods and a source of health-promoting compounds. Therefore, the aim of this study was to evaluate the chemical composition (proximate composition, fatty acids, volatile compounds, total phenolics, squalene, and β-sitosterol) of eleven pecan cultivars harvested in Rio Grande do Sul State (Brazil) and investigate their oxidative stability by the Rancimat method. ‘Barton’ is the main cultivar produced in Brazil and presented the highest protein, linoleic acid, and linolenic acid values and the lowest saturated fatty acid values, which provide health benefits. ‘Mahan’ showed the highest oxidation induction time, both in extracted oil and ground samples, low abundance of lipid oxidation compounds, low polyunsaturated fatty acids, high levels of oleic acid and β-sitosterol, which suggests potential for storage. ‘Stuart’ and ‘Success’ had the highest total dietary fiber values. Moreover, analysis showed that ‘Chickasaw’ and ‘Success’ had large quantities of compounds correlated to lipid oxidation, suggesting low stability for long-term storage. These results imply that the physicochemical characteristics and proximate composition of pecan nut cultivars from southern Brazil have variable parameters that may depend on their genetic variability.
Murley, T., B. Kelly, J. Adhikari, W. Reid, K. Koppel, 2020. A comparison of fatty acid and sensory profiles of raw and roasted pecan cultivars. J Food Sci. 85(9):2665-2672.
Five fatty acids comprise the bulk of the lipid content in pecans: palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid. Understanding the profiles of these fatty acids and how they relate to sensory characteristics may offer an explanation for flavor and flavor defects that may exist in certain cultivars of pecans. The objective of this study was to examine and compare fatty acid profiles of three cultivars of pecans (Major, Lakota, and Chetopa), over two crop years, under raw and roasted preparation methods, and understand the fatty acids association with sensory attributes. Percentages of palmitic, stearic, oleic, linoleic, and linolenic acids to total fatty acid content were determined using gas chromatography, and sensory profiles were generated using descriptive sensory analysis. Similar trends were seen across samples, with oleic acid comprising the majority of the total fatty acids and linolenic acid comprising the smallest percentage. There were significant differences in fatty acid content among cultivars and between pecans in the first and second crop year. Few associations were found between the fatty acids and sensory attributes, which suggest that combinations of the fatty acids contribute to certain pleasant or undesirable flavor attributes in the pecans. Subtle differences in fatty acid composition may lead to variation in flavor and flavor intensity or draw attention to or from certain attributes during consumption. Differences in crop year indicated that fatty acid content and therefore flavor are variable year to year. PRACTICAL APPLICATION: This study will help understand how fatty acid content of pecans varies from year to year. This should be taken into account when manufacturing products with pecans as the nutritional content of the product may change as the result.
Elizur, A., M.Y. Appel, L. Nachshon, M.B. Levy, N. Epstein-Rigbi, B. Pontoppidan, J. Lidholm, M.R. Goldberg, 2020. Clinical and molecular characterization of walnut and pecan allergy (NUT CRACKER Study). J Allergy Clin Immunol: In Practice. 8(1):157-165.e2
Background: Diagnostic methods for distinguishing walnut-allergic patients from walnut-sensitized but walnut-tolerant individuals are limited. Furthermore, characteristics of single walnut versus dual walnut-pecan allergy are lacking. Objective: To provide clinical and molecular characteristics of walnut- and pecan-allergic patients. Methods: A prospective cohort study of 76 walnut-sensitized patients was performed. Walnut skin prick test and serum measurements of specific IgE to walnut and its components were performed. Patients were challenged to walnut and pecan unless they regularly consumed walnut and pecan. Results: Of the 76 patients studied, 61 were diagnosed as walnut-allergic and 15 as walnut-tolerant. IgE levels greater than or equal to 0.35 kUA/L to Jug r 1 or 4 provided the best diagnostic method for identifying walnut-allergic patients (accuracy, 0.93). Of the 61 walnut-allergic patients, 49 were pecan-allergic whereas 12 were pecan-tolerant. None of the walnut-tolerant patients was allergic to pecan. Dual allergic patients had significantly lower walnut reaction dose (median, 100 mg vs 1230 mg; P < .001). IgE levels greater than or equal to 0.35 kUA/L to Jug r 4, low-molecular-weight vicilins, or high-molecular-weight vicilins best segregated dual walnut-pecan–allergic patients from single walnut-allergic patients. Inhibition studies demonstrated that walnut pretreatment completely blocked IgE binding to pecan, whereas in some patients, pecan incubation only partially blocked IgE binding to walnut. Conclusions: Walnut components are helpful in diagnosing walnut allergy and in identifying patients with pecan coallergy. Competitive ELISA indicates that pecan comprises a subset of the allergenic determinants of walnut.
Dikariyanto, V., S.E. Berry, G.K. Pot, L. Francis, L. Smith, W.L. Hall, 2020. Tree nut snack consumption is associated with better diet quality and CVD risk in the UK adult population: National Diet and Nutrition Survey (NDNS) 2008–2014. Public Health Nutrition. 23(17), 3160–3169.
Objectives: To examine associations of tree nut snack (TNS) consumption with diet quality and cardiovascular disease (CVD) risk in UK adults from National Diet and Nutrition Survey (NDNS) 2008–2014. Design: Cross-sectional analysis using data from 4-d food diaries, blood samples and physical measurements for CVD risk markers. To estimate diet quality, modified Mediterranean Diet Score (MDS) and modified Healthy Diet Score (HDS) were applied. Associations of TNS consumption with diet quality and markers of CVD risk were investigated using survey-adjusted multivariable linear regression adjusted for sex, age, ethnicity, socio-economic and smoking status, region of residency and total energy and alcohol intake. Setting: UK free-living population. Subjects: 4738 adults (≥19 years). Results: TNS consumers had higher modified MDS and HDS relative to non-consumers. TNS consumers also had lower BMI, WC, SBP and DBP and higher HDL compared to non-consumers, although a dose-related fully adjusted significant association between increasing nut intake (g per 4184 kJ/1000 kcal energy intake) and lower marker of CVD risk was only observed for SBP. TNS consumption was also associated with higher intake of total fat, mono-, n-3 and n-6 polyunsaturated fatty acids, fibre, vitamin A, thiamin, folate, vitamin C, vitamin E, potassium, magnesium, phosphorus, selenium and iron; and lower intake of saturated fatty acids, trans fatty acids, total carbohydrate, starch, free sugar, sodium and chloride. Conclusions: TNS consumers report better dietary quality and consumption was associated with lower CVD risk factors. Encouraging replacement of less healthy snacks with TNS should be encouraged as part of general dietary guidelines.
