Integration of Destructive and Non‐Destructive Analytical Determinations for Evaluating Quality of Fresh and Roasted Hazelnuts Subjected to Different Processing Temperatures
The internal quality of hazelnuts (Corylus avellana L.), particularly in terms of the degradation of fat components, is widely recognized as a key factor in determining the appropriate type of industrial processing. Additionally, the internal composition and volatile profile of hazelnuts change significantly based on different roasting conditions. The here reported study investigates the efficiency of Electronic Nose (E-nose) and Near-Infrared Spectroscopy (FT-NIR) technologies, combined with multivariate statistical techniques, for the rapid discrimination of hazelnuts subjected to different roasting conditions. Moreover, the study examines the ability of NIR to predict several key quality parameters in fresh and processed hazelnuts. Hazelnut samples were collected throughout the entire industrial processing chain, from delivery to roasting. The influence of three different roasting temperatures (140–150-160°C) was evaluated, keeping the roasting time constant at 24 min. Partial Least Squares models were computed to estimate moisture content, total soluble solids, protein content, acidity, and peroxide index through correlation with FT-NIR spectral data. Excellent regression performances were achieved for all quality parameters, except acidity, with correlations ranging between 0.951 and 0.918. Discriminant analysis models, specifically PLS-DA and Cluster Analysis, were used to assess the ability to discriminate hazelnuts subjected to different roasting conditions using FT-NIR and the Electronic Nose as non-destructive tools. Obtained results from these non-destructive techniques, particularly the volatile characterization GC/MS-performed, accurately reflected the differentiation of samples observed through traditional chemical analyses, effectively distinguishing different groups of samples based on roasting temperature. The use of non-destructive tools such as FT-NIR and E-nose during the post-harvest life and processing of hazelnuts offers an excellent solution for monitoring key quality parameters significantly important for the food industry.
https://doi.org/10.1002/fsn3.70095
The Impact of Daily Walnuts Consumption and Lifestyle Changes on Dyslipidemia.
The most frequent health condition linked to Cardiovascular Disease Is Dyslipidemia (CVD). This study showed how walnut consumption affected dyslipidemia patients when combined with a low-calorie diet and lifestyle modifications. A subsample of 120 people was chosen at random for intervention and divided into control (n=60) and experimental (n=60). Baseline blood lipid parameters and anthropometric measurements were assessed in both groups.A significant reduction in body weight (5.4%) and BMI (4.0%) of the experimental group was observed when compared to the control group (1.9% and 2.1%). However, for all parameters, there was a statistically significant (p<0.05) difference between pre-test and post-test in the experimental group, but non-significant (p>0.05) in the control group. Total cholesterol (11.5%), LDL cholesterol (15.3%), triglycerides (11.2%), VLDL cholesterol (9.0%), and enhanced HDL cholesterol (6.0%) were all significantly lower (p<0.05) in the experimental group.
Practical applications
This study showed that consuming 30g of walnuts per day and changing one's lifestyle can improve blood lipid profiles and help people lose weight. http://dx.doi.org/10.24966/FSN-1076/100129
Determination of volatile organic compounds by HS‐GC‐IMS to detect different stages of Aspergillus flavus infection in Xiang Ling walnut.
The aim of this study was to evaluate the performance of volatile organic compounds (VOCs) for evolution monitoring and early detection of Aspergillus flavus (A. flavus) contamination in walnuts. We successfully applied headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) to evaluate walnut VOC changes caused by A. flavus contamination. A total of 48 VOCs were identified in walnuts contaminated with A. flavus. After identification of VOCs, a heat map and principal component analysis (PCA) highlighted ethyl acetate-D, 3-methyl-2-butanol, and cyclohexanone as potential biomarkers specific to A. flavus contamination in walnuts. These results provided valid targets for the development of sensors to evaluate the early mold contamination in stored walnuts.
https://doi.org/10.1002/fsn3.2229
Identification of the promising Persian walnut (Juglans regia L.) genotypes among seedling-originated trees
Considerable genetic diversity among the native populations of Persian walnut (Juglans regia L.) provides a great opportunity to identify genotypes with valuable traits. In the present study, morphological and pomological diversity assessments of 362 walnut seedling origin genotypes were performed to identify superior genotypes. Significant differences were observed among the genotypes investigated in terms of the evaluated characters. Nut weighted from 5.53 to 19.24 g with an average of 10.67. The range of kernel weight was 1.78-9.28 g with an average of 4.83. Kernel percentage in 107 out of 362 genotypes studied was more than 50.00%. Multiple regression analysis (MRA) showed that kernel percentage was associated with kernel weight, nut weight, kernel filled, nut width, and shell thickness. Principal component analysis (PCA) showed that the characters related to nut and kernel size were correlated with the first component (PC1). Hierarchical cluster analysis (HCA) showed that the genotypes were clustered into two major clusters. Based on the most important commercial characters considered by breeders to select ideal walnuts, 15 superior genotypes were selected and are recommended for cultivation in the orchards and also can be used in breeding programs.
https://doi.org/10.1002/fsn3.2193
A comprehensive study of raw and roasted macadamia nuts: Lipid profile, physicochemical, nutritional, and sensory properties
Macadamia nuts have high nutritional value and positive health attributes. Changes to the composition and availability of these compounds during roasting contribute to product quality. In this study, changes to the chemical composition of lipids (fatty acids, triglycerides, and free fatty acids) and other phytochemicals were analyzed, and a sensory evaluation was carried out of two major varieties of macadamia nuts planted in China, after roasting. Only small changes in fatty acid (FA) content and a slight decrease in total triglycerides (TAGs) were observed after roasting. The free fatty acid (FFA) content and the peroxide value were increased by roasting. The total available polyphenol content increased by 25.6% and the oxidative stability index of kernels increased by 21.6%. The sensory scores for taste and aroma were doubled by roasting. Overall, the sensory, nutritional quality, and oxidative stability of roasted macadamia nuts were greatly improved, compared with raw nuts.
Synthesis of novel chemicals from cardanol as a product of cashew nutshell processing.
The conversion of the worldwide chemical production from fossil to sustainable resources is currently one of the most urgent tasks for the chemical industry. Based on this approach cardanol, a mixture of phenols with C15-chains as substituents is produced in some countries of the tropical zone from the processing of cashew nutshells. The paper reports the specific transformation of the aromatic moiety in this cheap material, and thus, the development of a novel route to potential useful green bifunctional chemicals in gram scale. Accordingly, cardanol was converted successfully in three steps into hexane-1,6-diols. The evaluation of appropriate synthesis methods and suitable conditions for each of these reaction steps is presented as an essential topic of these investigations. The target compounds synthesized in the reaction sequence are potential building blocks for future biomass-based chemicals and monomers for green polymeric materials, surfactants, and lubricants.
Different drying methods of Pistacia Atlantica seeds: Impact on drying kinetics and selected quality properties.
The effect of different drying procedures on the quality characteristics of Pistacia atlantica subsp. kurdica is addressed in this work. Using five different drying methods include microwave, oven (40 and 60°C), sun, and shade, P. atlantica were dried. The variations in moisture content, drying rate, major components of essential oil, and texture property were assessed at the start and at the end points of the drying process. Comparison of the drying methods indicated that microwave drying to be most effective in lowering moisture content, while the shade drying had the lowest rate among methods. In the case of microwave, the dried seeds had highest brittleness, while the highest score for the penetration force was observed in oven 40°C. Regarding major elements of the essential oil (α-pinene, α-terpinen-4-ol, myrcene, β-ocimene, β-caryophyllene, and limonene), there were no significant differences between the five drying techniques, nor compared to the fresh sample. To model the drying process, six thin-layer drying kinetic models were chosen. It was found that the Midilli-Kucuk model was the most suitable for explaining the drying curve of oven 40 and 60°C, microwave, and sun methods; Wang and Singh model was excellent to explain thin-layer shade drying behavior of the P. atlantica seeds. In conclusion, in this study, an opportunity is represented to apply the most effective procedures to decrease the drying period and to achieve a product with appropriate safety and quality features.
Improvement of oxidative stability and textural properties of fermented sausage via addition of pistachio hull extract.
The purpose of this study was to evaluate the effectiveness of pistachio hull extract (PHE) as an antioxidant and antimicrobial agent for preservation of dry fermented sausages during fermentation and storage period. Sausages were prepared using starter culture (Biobak K) and treated with three levels of PHE (500, 750 and 1,000 ppm). The results showed that PHE at concentrations of 500 ppm and 750 ppm decreased significantly (p < .05) the TBARS content of the sausage samples compared to control (without PHE). Moreover, PHE increased L* and a* value of samples during fermentation period but did not affect the color of samples during storage period. The PHE was also able to improve the chewiness and gumminess of the fermented sausage. Evaluation of microbial properties (total viable count, yeast and molds, lactic acid bacteria, staphylococci and Enterobacteriaceae) also showed that antimicrobial activity of PHE in fermented sausage.
Effects of different roasting methods on formation of acrylamide in pistachio.
Drying and roasting are conventional processes in the nut industry. However, roasting as an important procedure in nuts manufacturing may cause some physicochemical changes in nuts. Acrylamide is one of these chemical compounds that is formed due to the roasting process. Acrylamide is known as a neurotoxicant, carcinogen, and reproductive toxicant. In this study, raw and salted pistachios were roasted under three conditions including hot-air, infrared (IR), and microwave methods. Then, 80 pistachio kernels were analyzed by ultra-high-performance liquid chromatography. The results showed that all samples contained different ranges of acrylamide between 57 ± 0.86 and 851 ± 2.8 μg/kg. Besides, raw pistachios and sun-dried pistachios also contained acrylamide, with the amount of 57 ± 0.86 and 93 ± 1.07 μg/kg, respectively. The highest acrylamide amount was found in raw pistachio (unsalted) roasted by IR method, while lower acrylamide amount observed in the microwave method. The amount of acrylamide in salted and roasted pistachios was less than just roasted pistachios under the same conditions. Finally, in all the treatments, increasing temperature, time, voltage, and power lead to an increase in acrylamide levels. The results showed that acrylamide in the roasted pistachios may cause health problems. This study presents a novel investigation in the effects of roasting conditions (temperature, power, voltage, and time) on acrylamide content in pistachios.
Synbiotic yoghurt with walnut and cereal brittle added as a next‐generation bioactive compound: Development and characteristics.
The article presents a technology developed for the production of synbiotic Yoghurt with new bioactive filler based on natural components. The Yoghurt has prebiotic and sorption properties. A higher consumer appeal of the product developed has been substantiated; its characteristics compared with the Yoghurt of traditional production technology have been presented. The brittle, containing peeled walnuts, as well as barley, wheat, rye, oatmeal and buckwheat flakes, sugar, and water, was used as a filler. Optimum time and temperature regimes of boiling caramel mixtures and brewing raw walnut-cereal mass in the brittle have been selected. The formulation developed enables increasing the nutritional and biological values of the finished product. The research studies of the finished product involved an analysis of organoleptic, physicochemical, and microbiological points. When performing the tasks, the approved regulatory and technical documentation (GOST) was applied. Each measurement was carried out in triplicate. The physicochemical characteristics of the samples developed were compared with the requirements for the quality of fermented milk products. The nutritional and biological values were calculated. The increase in consumer properties, and nutritional and biological values of the finished dairy product was scientifically substantiated and experimentally confirmed.