Characteristics and composition of melon and grape seed oils and cakes

Watermelon (Citrullus vulgaris) and grape (Vitis vinifera) seeds were investigated for their nutritional quality and oil characteristics. The yields of seeds on an as is basis (edible portion) were 1.6 and 1.8% for grape and melon, respectively. The melonseed on a dry weight basis consisted of 53.6% testa and 46.4% kernel. The crude protein, fat and fiber content were 16.4, 23.1 and 47.7% for melon and 8.2, 14.0 and 38.6% for grape (dry weight basis). Both seeds were found to contain significant levels of Ca, Mg, P and K. The fatty acid profiles showed an unsaturated fatty acid content of 76.1% for melonseed oil and 88.6% for grapeseed oil. The predominant fatty acid in both seeds was linoleic acid. The iodine value, saponification number and acid value were 116, 248 and 0.97 for melonseed oil and 132, 194 and 1.59 for grapeseed oil. The amino acid profiles of both seed cake proteins were determined and compared with hen’s egg protein.     

Controlling Argan Seed Quality by NIR

The suitability of using visible/near infrared spectroscopy (Vis/NIR), as a rapid and non‐destructive technique for monitoring the quality of argan seeds (Argania spinosa Skeels) was studied. The analyzed parameters were the fatty acid composition of argan seed oil, seed moisture content, seed oil content and oil stability index (OSI). The ratio between major unsaturated and saturated fatty acids (U/S) during the oxidation assay at constant temperature was studied. Values from infrared drying were used as a laboratory reference for the moisture. Argan seed oil content was determined by Soxhlet extraction. A fatty acid analysis was carried out by gas chromatography and the OSI was determined by the Rancimat test. Predictive models of argan seed moisture, ratio U/S and OSI showed good accuracy. Therefore, Vis/NIR measurements can be used for controlling several argan seed quality parameters. This procedure might be of interest to the argan oil industry, which is currently in the process of modernization and expansion.     

Influence of blanching treatment and drying methods on the drying characteristics and quality changes of dried sardine (Sardinella gibbosa) during storage

The aim of this study is to examine the drying characteristics of blanched and unblanched sardine during indoor and open sun drying processes. Changes in temperature and relative humidity of the air during drying were recorded. The color, peroxide value (PV), thiobarbituric acid reactive substances (TBARS), free fatty acid (FFA) content, fatty acid composition, and sensory attributes of dried samples were also evaluated once a month for 5 months of storage. High drying rates were obtained in all samples at the start of drying and then decreased with increasing drying time. The highest drying rate and effective water diffusivity (D_eff) were observed in blanched sardine during open sun drying. Blanching treatment slowed down the FFA progression during product storage but adversely affected the color, PV, and TBARS content as well as sensory properties. Although sardine dried for a longer time under indoor drying conditions, it attained a stable moisture ratio that was lower than in open sun-dried samples. Indoor drying produced a quality stable product with less lipid oxidation and the desired moisture content, higher polyunsaturated fatty acids and sensory properties. Blanching treatment negatively affected the fish quality and is therefore not recommended for commercial sardine drying.     

Characterization of artisanally and semiautomatically extracted argan oils from Morocco

The present study was conducted to know the possible influence of the seed treatment, method of extraction and geographical origin on the quality and chemical composition of argan oil. Artisanally and semiautomatically extracted argan oils, from roasted and unroasted seeds, from interior and coast areas, were studied. The quality parameters analyzed were acid value, peroxide value, K₂₃₂ and K₂₇₀, triacylglycerols and fatty acid composition, polar compounds, total phenols, tocopherol content and oil stability index (OSI). Seed treatment and extraction method showed a higher influence on quality parameters than geographical area; the quality parameters of the different oils were discussed. The total phenolic content in all analyzed samples was lower than 10 ppm. γ‐Tocopherol was the major tocopherol (84.4–86.4%) with a high contribution to the total tocopherol content (383–485 ppm). The OSI of the argan oil samples were well correlated (R = 0.97) with the tocopherol contents. The argan oil samples obtained from roasted seeds presented higher stability (26–38 h) than the oils from unroasted seeds (16–32 h).     

The Effects of Infrared Roasting on HCN Content,Chemical Composition and Storage Stability of Flaxseed and Flaxseed Oil

Flaxseeds were roasted at 1150 W/m² radiation intensity with short and medium wave infrared (IR) emitters for specific durations, which provided good visual and sensory quality. The effects of IR roasting on color properties, hydrogen cyanide (HCN) content, tocopherols and fatty acid composition of the flaxseed and flaxseed oil were investigated. Further, flaxseeds were stored for 6 months and free fatty acid content and peroxide values were followed at 1-month intervals to understand the effect of IR treatment on hydrolytic and oxidative stability. HCN content of the flaxseeds was reduced up to 59% with IR roasting. Tocopherol content of the IR roasted flaxseed oil was higher than that of the control. No notable variation was observed in fatty acid composition with regard to IR treatment. Free fatty acid content of IR roasted flaxseeds did not increase during storage, while peroxide value of the seeds significantly increased up to 95 mEq O₂/kg oil.     

Tunisian Pistacia atlantica Desf. Extraction Process: Impact on Chemical and Nutritional Characteristics

Plant materials have been used in different fields such as therapeutics, cosmetics, and energy for ages. Several studies have investigated seeds, whether common or not, in order to ensure a better valuation of natural resources. Among these, Pistacia atlantica Desf. has been the subject of several works on its characterization and valorization. Among the current trends in sustainable development and environmental protection, valorizing natural wild plants via green chemistry has become prevalent. One of these plants, Pistacia atlantica Desf., is a tree that grows in arid and semi-arid areas, notably in Tunisia, and produces seeds rich in oil. In this study extracting the oil from its seeds is tried by three methods (supercritical carbon dioxide (CO₂), pressure, and hexane), and the efficiency of these extraction processes is compared in order to obtain the best yield and maximize its valorization in a variety of industrial fields. The obtained oil is found to be rich in polyunsaturated fatty acids, namely linoleic and oleic acids, with a similar acidic composition among all extraction methods. The tocopherol composition of the oil is determined using high performance liquid chromatography. The total polyphenol content is determined using the Folin-Ciocalteu colorimetric analysis method. The results show that the seed oil of Pistacia atlantica Desf. extracted by supercritical CO₂ gives the highest extraction yield (25%) and the lowest acidity and peroxide values with a high degree of oxidation at 232 and 270 nm. This method also gives the highest content of alpha, gamma, and delta tocopherol as well as total phenolic content compared to the other extraction methods. The composition of chlorophylls and carotenes in the seed oil of Pistacia atlantica Desf. is determined. Besides, the analysis of the sterol composition reveals that β-sitosterol is still prevailing. Among all the tested extracts, the supercritical CO₂ extract demonstrates the best antioxidant performance against the tested radicals. The oil extracted by supercritical carbon dioxide (CO₂) is of a higher quality compared to that extracted by pressure and by hexane. Practical applications : The Pistacia atlantica Desf. oil exhibits interesting physicochemical and biological characteristics. The type of extraction affects the quality of the major and minor components in the seeds. However, the supercritical CO₂ method produces a better oil quality with the presence of antioxidants such as tocopherols and polyphenols. In fact, it is found that the oil extracted by the three methods has an important sterolic profile with the predominance of β-sitosterol. According to the classification of vegetable oils, unsaturated fatty acids of atlas pistachio oil can be categorized as oleo linoleic oil, which enhances its nutritional value. Having these characteristics, the use of this oil can be considered in agrifood products.     

Soybean Seed Quality Characteristics in Response to Indigenous Bradyrhizobium Inoculation and N Fertilization in Kashmir–Pakistan

The objective of this study was to quantify changes in soybean seed quality characteristics in response to indigenous Bradyrhizobium inoculation and N fertilization applied under field conditions during the years 2009 and 2010. Seven indigenous Bradyrhizobium isolates were isolated from the different locations under the foothills of great Himalayas Rawalakot Kashmir, Pakistan. The field isolates were compared to a reference strain (exotic) TAL102, three N fertilizer rates and to an un‐inoculated control. The seed oil content, fatty acid composition, seed N, P and K concentration and seed N, P and K uptake were quantified. Bradyrhizobium inoculation and N fertilization significantly increased oil content compared to the un‐inoculated control. The seed oil content varied between 16.2 and 21.5 %, highest in the seeds treated with indigenous Bradyrhizobium strains NR₂₂, NR₂₅ and NR₃₅, and mainly composed of linoleic acid (47 %), and oleic acid (24 %). Inoculation and N fertilization both decreased the saturated fatty acids (palmitic and stearic) and increased unsaturated fatty acids (linoleic acid and oleic acid). The mineral nutrient content of N, P, and K and their accumulation in seed increased by 2–3‐fold compared to the corresponding control. Indigenous Bradyrhizobium strains were able to generate the highest values for seed oil content (NR₂₂, NR₂₅, and NR₃₅), unsaturated fatty acids, i.e. linoleic acid and oleic acid (NR₂₅, and NR₃₅) and N, P and K uptake (NR₂₀, and NR₂₂). There were noticeable differences among the treatments in terms of essential fatty acid, oil, and mineral nutrient content. The study demonstrates the potential benefits of using indigenous Bradyrhizobium strains in order to achieve high quality soybean seeds that can be used as a balanced health product.     

Characterization of Turkish Olive Oils by Triacylglycerol Structures and Sterol Profiles

A characterization study of Turkish monovarietal olive oils using chemical variables such as fatty acid, sn‐2 fatty acid, triacylglycerol, and sterol composition is presented. A total of 101 samples of Olea europaea L. fruits from 18 cultivars were collected for two crop years from west, south, and southeast regions of Turkey. Olives were processed to oil and olive oil samples were evaluated for their triacylglycerol structures and sterol composition. Oleic acid content ranged from 60.15 to 80.46 % of total fatty acids and represented 70.90–89.02 % of sn‐2 position triacylglycerols. Major triglycerides of oil samples were triolein, palmitodiolein, dioleolinolein, palmitooleolinolein, dipalmitoolein, and stearodiolein. Triolein values were between 24.72 and 48.64 % and compatible with the fatty acid composition. Total sterol content varied from 1,145.32 to 2,211.77 mg/kg and Edremit yagl?k stood out because of its high sterol content. A one‐way analysis of variance revealed significant differences for variables among cultivars. Principle component analysis enabled the classification of common varieties on the basis of analytical data. Sterol composition achieved more relevant discrimination than fatty acid and triglyceride composition. Classification according to geographical origin was performed by discriminant analysis.     

Propolis and carnauba wax-based safflower oil oleogels as fat substitutes in cakes: Production,oxidative stability,and characterization

In this study, safflower oil oleogels were made using propolis wax and carnauba wax in three different concentrations each, and their effectiveness as a fat substitute in cake was evaluated afterward. Oleogels' oxidative stability and characterization were looked into. In oleogels, the oil binding capacity, solid fat content, and crystallization time were all assessed. The cakes underwent an examination for moisture content, texture, and sensory evaluation. Additionally, analyses of fatty acid composition, free fatty acidity, oxidative stability (peroxide value, conjugated diene-triene), 3-monochloropropane-1,2-diol (3-MCPD), and glycidyl were carried out both before and after baking in oleogels and shortening. Several of the physical, textural, and sensory qualities of the oleogel-based cakes were acceptable when compared to those of the shortening-based cakes. The general acceptability of cakes made with carnauba wax was very high and almost under control. The acceptability of cakes made with propolis wax oleogels was lower than this. The study of these criteria has shown that safflower oil-based carnauba and propolis wax oleogels can be utilized to produce high-quality, healthful cakes with a high amount of unsaturated fatty acids. Practical Applications : To replace fat phases in cake products high in saturated fatty acids and to enhance the fatty acid profile of the cakes, safflower oil-based oleogels with propolis wax and carnauba wax are a very good option. The results obtained provide useful information for the production of high-quality cakes with higher unsaturated fatty acid content, recommended for a healthier diet, with these oleogels containing different concentrations of oleogelator.     

Heat pump drying of grape pomace: Performance and product quality analysis

Abstract

Grape is one of the most popular fruits and various types of grape have been cultivated by more than 100 countries around the World. The wine and juice industry produces large quantities of by-product, called grape pomace (GP) as an industrial waste and it consists of skins, seeds, and stems. Various processes such as separation, pressing, drying, and milling are applied to benefit from its health effects. In this study, the seeded black GP Kalecik karas? (Vitis vinifera) was dried in an assisted closed cycle heat pump dryer (HPD) designed for high-moisture products to investigate the drying behaviors of GP. The effects of drying air temperature on bioactive properties and the drying characteristics of GP, and performance of system have discussed. Experiments were carried out at two different temperatures (45 and 50°C) and air velocity of 1.0 m/s. It was seen that increasing temperature decreased the drying time, coefficient of performance of whole system (COP_ws), and specific energy consumption (SEC). The average values of COP_ws for temperatures 45°C and 50°C were calculated as 3.28 and 3.10, respectively. The drying efficiencies (DE) at drying air temperature of 45°C and 50°C ranged from 2 to 12% and from 2 to 15%, respectively. Additionally, result of analysis has indicated that using a HPD at lower temperatures increases performance of system despite of higher energy input. Bioactive properties of dried samples at drying air temperature of 45°C are better than 50°C. The results show that drying the GP at low temperature is more suitable for product quality. For this reason, heat pump may be preferred. It shows that this drying system with higher capacities in the future can be recommended as an alternative technique in terms of energy usage, drying time, and performance of system.     

Effect of air temperature and velocity on moisture diffusivity in relation to physical and sensory quality of dried pumpkin seeds

Understanding the effect of drying process parameters on food quality is helpful in process optimization and control. The objective of this work is to understand the effect of mild and harsh effective moisture diffusivity (D_eff), varied by air temperature and velocity, of drying processes on the physical and sensory quality of flat food products. Pumpkin seeds were selected as a food representative. It was found that increments of air temperature and velocity resulted in increased D_eff and brown color on seed hull surfaces and embryos, but decreased hardness of seed embryos. Changes in taste and aroma of seed embryos were able to be sensed. Indicating that D_eff is related to seed physical quality. Similar phenomena occurred with both tray and fluidized bed drying. Air temperature, velocity, and D_eff should be controlled to ensure the best dried flat food products. Mild drying conditions are potentially preferred for good physical and sensory quality.     

Virgin grape seed oil: Is it really a nutritional highlight?

In comparison to refined grape seed oil which is neutral in taste and smell, the virgin oil is characterized by a pleasant vinous and fruity aroma, which also reminds of raisins if high‐quality raw material is used for the production. Difficulties arise from the susceptibility of the raw material to microbial and enzymatic deterioration as a result of the high moisture content after pressing the juices from the grapes. Grape seed oil has a high content (70%) of linoleic acid, whereas the total part of unsaturated fatty acids amounts to about 90%. In comparison to other edible oils, the oil contains, in addition to tocopherols, antioxidant‐effective tocotrienols. During the oil pressing process, only a small amount of phenolic compounds is transferred into the oil (0.01 mg/g), while most of these nutritionally interesting components remain in the press cake. Here, the content of phenolic compounds is about 2000 times higher. During storage of virgin grape seed oil, the pleasant sensory attributes change, and more and more degradation products like ethyl acetate, acetic acid or ethanol are detectable. Parts of the seed material, which come into the oil during pressing, result in a faster impairment of the oil.     

Effect of Gamma Irradiation on Biochemical Properties of Grape Seeds

In the present study, grape seed samples (Alicante Bouschet, Cabernet Franc, Cinsault, Merlot, Shiraz) were treated with 1.0, 3.0, 5.0, and 7.0 kGy of gamma radiation. Effect of irradiation dose on free fatty acids (FFA), peroxide value (PV), sterol, fatty acid composition, phenolic content, antioxidant activity of the seed oils, and chemical (dry matter, fat, ash, total sugar, invert sugar) changes of grape seeds were determined. Regarding fatty acid composition, oleic acid (C18:1) and linoleic acid (C18:2) levels decreased. β-sitosterol content with a highest percentage among sterols in grape seed oils decreased due to gamma irradiation. Generally gamma irradiation increased free fatty acids and peroxide value of the oils; however, phenolic content and antioxidant capacity of grape seeds decreased.     

Effects of Dehulling Sacha Inchi (Plukenetia volubilis L.) Seeds on the Physicochemical and Sensory Properties of Oils Extracted by Means of Cold Pressing

Sacha Inchi (Plukenetia volubilis L.) is a plant native to the Peruvian Amazon, with great expansion because of the high industrialization potential of its seeds (SIS). The Sacha Inchi oil (SIO) is commonly obtained by pressing the SIS, and it is of high commercial value because of its excellent nutritional properties. In this study, we investigated the effects of the dehulling of SIS on the physicochemical and sensory properties of the SIO extracted by means of cold pressing. The fatty acid composition, Fourier transform infrared (FTIR) spectra, density, refractive index (RI), acid value (AV), peroxide value (PV), p-anisidine index (p-An), oxidative stability index (OSI), color, and sensory profiles of the SIO samples were evaluated. The oils obtained from whole SIS showed similar fatty acid profiles, physicochemical properties, and sensory profiles to those extracted from dehulled SIS. After 60 days of storage, the total oxidation values of both SIO samples significantly increased, but there were no significant differences between oils from whole and dehulled SIS. Thus, the dehulling process could be avoided without affecting significantly the quality of the obtained oils.     

Cherry leafroll virus: Impact on olive fruit and virgin olive oil quality

We performed a survey on the yield, quality, and chemical characteristics of virgin olive oils from two olive varieties in Croatian Istria: Frantoio and Ascolana tenera, on Cherry leafroll virus‐infected and virus‐noninfected trees and on two harvest dates. Free acidity, peroxide value, specific spectrophotometric absorptions at 232 and 270 nm, fatty acid composition, total phenols, o‐diphenols, oil color, and pigments were determined. Infected olives had lower oil yield and maturity index versus healthy ones. Oils from infected fruits had significant lower value of K₂₃₂ and K₂₇₀ and very elevated total phenols content compared to those obtained from healthy olives. Infected Frantoio gave a lower content of o‐diphenols than the healthy ones, which is in contrast to infected Ascolana that had higher values. The aim of this study is to determine the chemical changes in virgin olive oils from healthy and infected trees related to virus influence. According to our knowledge, this is the first survey on the possible influence of viruses on olive fruits, oil yield, and virgin olive oil quality. Practical applications : There are only few papers which analyze the influence of viruses on crops (especially influence on wine quality) and their effects on yield or other agronomic parameters. This work evaluates for the first time the impact of Cherry leafroll virus on the quality of virgin olive oil obtained from Frantoio and A. tenera varieties in terms of basic parameters related to the hydrolitic and oxidative status, content in antioxidant compounds, and in pigments as well as in fatty acid composition.     

Evaluation of Potential and Real Quality of Virgin Olive Oil from “Campos de Hellín” (Albacete, Spain)

The regulated physicochemical and sensory parameters, stability parameters and fatty acid, sterol and triterpenic dialcohol composition of the olive oils from the varieties Arbequina, Benizal, Cornicabra, Cuquillo, Injerta, Manzanilla de Sevilla, Manzanilla Local, Picual and Negrilla, grown in the Campos de Hellin, were analyzed. Regarding potential quality, all the oil samples were classified in the “extra virgin” category according to the regulated parameters. The oils from the varieties Cornicabra and Picual showed remarkably high stability, due to their high total phenol content. The oils from the Benizal variety stood out due to their high campesterol and low total sterol content, exceeding and not reaching, respectively, the limits set by European regulations. This seems to be an intrinsic characteristic of this variety. When the real quality was analyzed, two clearly differentiated groups were observed: on one hand, oils from the Arbequina variety, and on the other hand, oils from the Picual variety and oils mixed from different varieties (Blend). The great number of olive varieties grown in the Campos de Hellin area enables the production of better balanced oils, producing high quality blended oils since the mixing of different varieties may compensate the deficiencies of monovarietal oils.     

Improving olive oil quality with double protection: Destoning and malaxation in nitrogen atmosphere

Effect of destoning and malaxation in nitrogen atmosphere on oxidative stability, fatty acid and sterol composition of extra virgin olive oil (EVOO) were investigated in industrial scale. Olives of ‘Edremit yaglik’ cultivar were processed with a two phase centrifugal system with or without stones, in nitrogen or air atmosphere. Results have shown that either N₂ flush or destoning did not make any contribution to the sterol and fatty acid composition. Malaxation in nitrogen atmosphere extended induction time, raised phenolic, tocopherol contents and antioxidant potential of oils. Destoning also increased oxidative stability but lowered carotenoid and chlorophyll contents of oils. Among all treatments, the combined effect of destoning and malaxation in nitrogen atmosphere achieved the production of EVOO with the highest quality.     

Improvement of Oil Quality in Soybean [<Emphasis Type="Italic">Glycine max </Emphasis>(L.) Merrill] by Mutation Breeding

Low oxidative stability, off-flavor and rancidity are the major drawbacks of soybean oil. Modification of the fatty acid composition of soybean [Glycine max (L.) Merrill] oil can improve its quality and value for processors and acceptability among consumers. Mutation breeding of soybean was therefore initiated with the objective of identifying stable soybean mutants with altered fatty acid composition for improved oxidative stability and nutritional quality. Seeds of soybean cultivar ‘MACS 450’ were treated with γ-radiation and/or ethyl methane sulfonate (EMS). The harvest of M₁ plants was evaluated for fatty acid composition by gas chromatography. Highly significant variation in all the fatty acids except palmitic acid was observed. Treatment of EMS in higher concentrations as well as combined treatment of both the mutagens, i.e., γ-radiation and EMS were effective in increasing the variability for the fatty acid content in soybean oil. The variability was skewed towards high levels of oleic (35–42%) and low levels of linolenic acid (3.77–5.00%). M₃ and M₄ generations of desirable variants were analyzed for the stability of the mutated trait_. Only high oleic variants were stable in M₃ and M₄ generations. Based on fatty acid values, oxidative stability index (OSI), nutritional quality index (NQI) and ratio of essential fatty acids (ω₆/ω₃) were calculated for the control and M₂, M₃ and M₄ generations. The ω₆/ω₃ ratio in all the high oleic mutants was within the World Health Organization (WHO) recommended value (5–10%). A significant positive correlation between OSI and oleic acid content (P < 0.001) indicated improved oxidative stability of the oil while retaining nutritional quality. These high oleic lines could be utilized further in breeding programs for improvement of soybean oil quality.     

Effect of Roasting on Physicochemical Properties of Wild Almonds (Amygdalus scoparia)

Roasting enhances sensory quality of wild almonds (Amygdalus scoparia). The aim of the study was to evaluate the use of microwaves (480 W for 3 or 4 min) in roasting of wild almonds in comparison with traditional Spanish (165 °C for 20 min) and Iranian (soaking in 20 % NaCl in water for 30 min, drying at 60 °C for 2 h and roasting at 135 °C for 20 min) hot‐air processes. The influence of roasting wild almonds on moisture and oil contents, crispness, fatty acid profile, volatile compounds, and odour intensity was investigated. Roasting causes changes in appearance, texture and flavour, due to dehydration, browning, lipid oxidation, and diverse structural changes. The moisture content and hardness of the samples significantly decreased with all roasting methods. Roasting resulted in higher amounts of characteristics aroma compounds and only microwave roasting increased the oil content. The final recommendation is that microwave roasting at 480 W for 4 min led to roasted almonds of high physicochemical [dark and intense colour (L*44.9, a*8.4, and b*19.6), the highest content of total volatile compounds (132 mg kg^?1), 85.2 % of unsaturated fatty acids], and sensory (high intensity of “roasted almond” aroma) quality. Microwaves can be used for roasting wild almond as a quick, safe, and economical method.     

A lipidomic approach for profiling and distinguishing seed oils of Hibiscus manihot L., flaxseed,and oil sunflower

As important oil crops in Inner Mongolia, sunflower, and flaxseed had distinct lipid profiles in seeds. As an emerging cash crop, Hibiscus manihot L. has strong potential market competitiveness. In this study, the lipidome, fatty acid composition and quality characteristics of flaxseed, H. manihot L., and sunflower seed oils were analyzed and compared. A total of 270 distinct lipids were identified and analyzed with an emerging detection approach—lipidomics, which illustrated the tremendous difference among the samples. triacylglycerol, diacylglycerol and polar lipids were the most abundant lipids in all samples. H. manihot L. seeds contained higher saturated and monounsaturated fatty acids and lower polyunsaturated fatty acids. H. manihot L. seed oil had the longest oxidative stability index time, high content of vitamin E and total phenolics, while flaxseed oil embodied the lowest oxidative stability. The peroxide value and acid value of the three oils were within the allowable range of Chinese national standards.