Tocopherol content,peroxide value and sensory attributes in roasted peanuts during storage

The objective of this study was to determine changes in tocopherol content, peroxide value (PV) and sensory attributes from roasted peanuts during storage at 40 °C. There were no differences in tocopherol contents between roasted and raw peanuts except in α‐tocopherol content that decreased after roasting. All tocopherol contents decreased during storage. On the contrary, lipid oxidation indicators such as PV and the intensity ratings of oxidised and cardboard flavour increased during storage. On the other hand, the intensity ratings of roasted peanutty flavour decreased with storage time. Good correlations were observed between tocopherol contents and PVs. Tocopherol contents could be used as indicator of oxidative state in peanut products.     

Effect of storage on chemical and sensory profiles of peanut pastes prepared with high‐oleic and normal peanuts

BACKGROUND: Peanut paste and peanut butter have high oil contents and are thus susceptible to developing rancidity and off‐flavours through lipid oxidation. Preservation of the chemical and sensory quality of these products is one of the main problems in the peanut industry. The purpose of this study was to compare the chemical and sensory stability of peanut paste prepared with high‐oleic peanuts (cv. Granoleico, GO‐P) with that of peanut paste prepared with normal peanuts (cv. Tegua, T‐P) from Argentina. RESULTS: Chemical (peroxide and p‐anisidine values and conjugated dienes) and sensory (roasted peanutty, oxidised and cardboard flavours) indicators of lipid oxidation were measured in peanut pastes stored at 4, 23 and 40 °C. Chemical indicator values and oxidised and cardboard flavours showed lower increments in GO‐P than in T‐P during storage. T‐P had significantly higher peroxide value than GO‐P. Roasted peanutty flavour showed a lower decrease in GO‐P. Peanut paste prepared with high‐oleic peanuts had four (at 4 °C), two (at 23 °C) and three (at 40 °C) times longer shelf‐life than peanut paste prepared with normal peanuts. CONCLUSION: These results indicate that high‐oleic Granoleico kernels provide peanut paste with higher protection against lipid oxidation. Copyright © 2010 Society of Chemical Industry     

Effects of processing conditions and packaging material on the quality attributes of dry‐roasted peanuts

Five different processing conditions of raw shelled unblanched peanuts were investigated. The first two treatments involved soaking the peanuts in tap water for 10 and 30 min respectively, then mixing thoroughly with dry NaCl before roasting. Another two treatments involved soaking the peanuts in saturated brine solution for 10 and 30 min respectively before roasting. Unsalted roasted peanuts served as the control. Packaging and storage studies were carried out by packaging the differently treated dry‐roasted peanuts in four different packaging materials and storing them under three different relative humidities for 3 months at ambient temperature. Proximate composition, NaCl content, peroxide value and thiobarbituric acid value were determined and sensory evaluation tests were carried out. Salting was found to improve the taste, flavour and overall acceptability of dry‐roasted peanuts but had no effect on shelf‐life. Peanuts treated in saturated brine solution for 30 min before roasting were the most preferred. The control packaging material, 18 µm transparent polyethylene, was found to be inadequate for protecting the quality attributes of dry‐roasted peanuts, with mould growth being observed on the 42nd day of storage at 80% relative humidity. However, acceptable results were obtained with 45 µm transparent polypropylene. The mean sensory scores and objective tests were found to be negatively correlated. © 2002 Society of Chemical Industry     

In a nutshell: prospects and challenges on coatings for edible kernels

Edible kernels have been popular food items since ancient times. Although in-shell nuts are naturally protected and relatively shelf stable, convenience demands require their commercialization in shelled form. However, whereas shelled kernels are more convenient, they are more exposed to oxygen, and thus more susceptible to oxidative rancidity and loss of crunchiness, which negatively affect the product acceptability. In this review, we discuss the role of edible coatings in extending stability of edible kernels, which is an opportunity to be better explored by the industry. The discussion also includes the role of antioxidants in the context of active coatings. Finally, future prospects and research challenges are addressed. © 2019 Society of Chemical Industry     

Effects of incorporating roasted lupin (Lupinus angustifolius) flour on the physicochemical and sensory attributes of beef sausage

The effects of incorporating lupin flour on the physicochemical and sensory characteristics of beef sausages were explored. Lupin (Lupinus angustifolius) flour was roasted, then hydrated to match the moisture content of beef meat. The beef sausage samples were manufactured for six treatments by replacing beef with hydrated lupin flour from 0% to 36% (w/w). Proximate analysis revealed that carbohydrate (dietary fibre) level was increased from 9.62% to 19.31%, whereas fat content was decreased from 11.62% to 7.91%. Inclusion of lupin flour increased the meat emulsion stability (fluid released decreased from 9.35% to 1.53%) and decreased cooking loss from 22.70% to 14.30%. Softer texture and greater adhesiveness were observed in lupin-incorporated formulations. Sensory evaluation indicated no significant difference between control and 12% lupin-enriched beef sausage formulation in appearance, aroma, flavour and overall liking, suggesting lupin flour can be added to beef sausage at this level without compromising consumer acceptance.     

Properties of a thermal-processed beverage prepared from roasted partially defatted peanuts

The effects of two thermal processing methods on physical and sensory properties of a beverage prepared from finely ground, partially defatted roasted peanuts ( Arachis hypogaea ) were determined. Samples were either bottle-processed at 72 °C for 2 min or 111 °C for 8 min after homogenizing at 72 °C, or kettle-pasteurized for 2 min at 72, 77 or 82 °C before homogenizing at 72, 77 or 82 °C, respectively. Harsher thermal processing parameters increased the suspension stability and viscosity of bottle-processed beverage by 175 and 87%, respectively, but had no influence on kettle-pasteurized beverage. Total solids (%) and colour were not adversely affected by thermal processing. Beverage which was kettle-pasteurized and homogenized at 72 °C had low viscosity (6.1–8.4 cps), typical roasted peanut flavour and little or no chalky mouthfeel, irrespective of whether carrageenan (stabilizer) or mono-diglyceride (emulsifier) were added to the formulation. Kettle-pasteurizing before homogenizing (20.7 × 10⁶ Pa) showed potential for producing beverages with physical and sensory attributes similar to commercial cow milk products.     

可食膜对裹衣花生氧化抑制作用的研究

采用大豆分离蛋白、壳聚糖和豌豆淀粉为成膜基材,制备出不同的可食膜。测定了涂抹不同可食膜对衰衣花生贮藏期间过氧化值含量的影响。研究表明,可食膜有较强的抑制裹衣花生贮藏周期内发生氧化的能力。65℃下贮藏25d后,与对照组相比,可食膜液处理的裹衣花生过氧化值含量均降低到0．2g／100g以下,可有效延长裹衣花生的贮藏期。     

感官评价优化冷却牛肉可食性涂层的研究

研究以大豆分离蛋白、豌豆淀粉和三乙酸甘油酯为主要原料的可食性涂层对冷却牛肉感官品质的影响。以冷却牛肉的感官评价值为响应值,采用响应面分析方法优化可食性涂层的最佳配方。实验结果显示,当可食性涂层中大豆分离蛋白含量为3.00g/100mL、豌豆淀粉含量为4.90g/100mL和三乙酸甘油酯为1.49g/100mL时,冷却牛肉的感官品质最佳,并且显著优于未包装的冷却牛肉,验证实验表明预测值与真实值相对偏差仅为2.4%,为可食性涂层在冷却肉保鲜中的应用提供了理论支持。     

可食性牦牛奶酪改性保鲜膜的性能研究

采用正交分析试验设计方法,研究了牦牛乳酪蛋白质量分数、pH值和成膜温度等对可食性膜各项性能的影响,并确定了最佳的成膜条件和影响膜性能的各项指标.结果表明,最佳成膜条件为甘油含量1％、pH值为6.0、烘干温度30℃、相对湿度40％、酪蛋白质量分数7.5％.在此条件下制备的薄膜,其最大承受力58.6 N/cm2,拉伸强度为21.83 MPa,伸长率为17.50％,水蒸气透过系数为21.47 g/（m2·h）,氧气透过系数为0.17 g,/（m2·d·Pa）,膜性能最优.     

Enzymatic and Autoxidation of Defatted Peanuts

Ground, blanched, raw, and roasted peanuts with varying oil contents were analyzed for oxidation products. Peroxide values (PV) of blanched, ground raw (BRAW) peanuts, demonstrating enzymatic oxidation, and heat-treated rancid roasted peanuts (RRST), demonstrating autoxidation, exhibited decreases (p ≦ 0.05) with decreasing oil content. The Oxidative Stability Index (OSI) time at 110 °C increased (p < 0.05) with decrease in oil content of raw (BRAW) and roasted (BRST) ground peanuts. A higher OSI indicated more oxidative stability, thereby supporting the hypothesis of higher potential for autoxidation at higher oil contents. In addition, BRST exhibited a shorter OSI than BRAW, indicating slower autoxidation in BRAW. Roasted peanutty odor, burnt odor, and roasted peanutty flavor, rancid/oxidized flavor, and burnt flavor scores of rancid roasted peanuts decreased (p ≦ 0.05) with decreasing oil content.     

Characterization of edible coatings consisting of pea starch, whey protein isolate, and Carnauba wax and their effects on oil rancidity and sensory properties of walnuts and pine nuts

Edible coatings made of whey protein isolate (WPI), pea starch (PS), and their combinations with carnauba wax (CW) were prepared and characterized. WPI combined with CW formed stable emulsion while PS with CW formed unstable emulsion and both formulations produced non-homogeneous films. Addition of PS to WPI: CW combination at the ratio of 1:1:1, respectively, resulted in stable emulsion and homogenous films. The emulsion PS: WPI: CW (1:1:2) was stable and formed a continuous film but had less homogenous droplets size distribution when compared to 1:1:1 film. Combined films had a reduced tensile strength and elongation compared to single component films. WPI : CW (1:1) films had higher elastic modulus than the WPI films, but the modulus reduced by the addition of PS. All the coating formulations were effective in preventing oxidative and hydrolytic rancidity of walnuts and pine nuts stored at 25 °C throughout the storage (12 d) but were less effective at 50 °C. Increasing the concentration of CW from 1:1:1 to 1:1:2 in PS: WPI: CW formulation did not contribute in further prevention of oil rancidity at 25 °C. Using of PS: WPI: CW (1:1:1) coating on both nuts significantly (P < 0.05) improved their smoothness and taste but the PS: WPI: CW (1:1:2) coatings imparted unacceptable yellowish color on walnuts. PRACTICAL APPLICATION: Edible coating of walnuts and pine nuts by whey protein isolate, pea starch, and carnauba wax reduced the oxidative and hydrolytic rancidity of the nuts and improved sensory characteristics.     

Visualization of sensory profiling data for performance monitoring

Simple graphical techniques can be utilized to investigate the performance of individual assessors and to detect individual differences among assessors in a sensory panel. By visualizing different type of information in a set of various plots the panel leader can extract relevant information without the need of extensive knowledge in statistics. The joint information content gained from the plots can then be used as a basis for selective training in order to improve performance of single assessors and the panel as a whole.     

Effect of gamma irradiation on the physico‐chemical and sensory properties of raw shelled peanuts (Arachis hypogaea L.) and pistachio nuts (Pistacia vera L.)

Backround The present study evaluated the quality of raw peanuts and pistachio nuts as a function of irradiation dose in order to determine dose levels causing minimal undesirable changes to these products. Physico‐chemical (colour, peroxide value, hexanal content, fatty acid composition, volatile compounds) and sensory (colour, texture, odour, taste) properties of raw peanuts and pistachio nuts were determined after irradiation at doses up to 7 kGy. Results Results showed an eight‐ and seven‐fold increase in peroxide value and a twelve and five‐fold increase in hexanal content after irradiation at a dose of 7 kGy for peanuts and pistachio nuts, respectively. An increase was also observed in saturated fatty acids (20.51–28.28% and 15.24–24.87%) with a parallel decrease in unsaturated fatty acids (79.49–71.72% and 84.76–75.13%) for peanuts and pistachio nuts, respectively. Likewise, volatile compounds such as aldehydes, alkanes, ketones and alcohols comprising secondary oxidation products of peanut and pistachio nut lipids increased after irradiation. Pistachio nut colour parameter a* and to a lesser extent parameters, L* and b* decreased after irradiation leading to a slight but noticeable darkening in product colour while colour parameter L*, b* and a* of raw peanut remained unchanged by irradiation up to 7 kGy. Conclusion Based on sensory evaluation, peanuts and pistachio nuts become unacceptable for consumption when irradiated at doses higher than 3 kGy. Copyright © 2009 Society of Chemical Industry