Phytonutrient content and oil quality of selected edible oils upon twelve months storage

Edible oils contain naturally occurring phytonutrients and therefore exhibit numerous beneficial health effects. However, the phytonutrients tend to degrade in different extent with storage duration and temperature. In this study, the impact of storage conditions on the stability of phytonutrients, including vitamin E, carotenoid, phytosterols and squalene, and oil quality, including free fatty acids (FFA), peroxide value (PV), anisidine value (AV), and oxidative stability index (OSI) of red palm-pressed mesocarp olein, palm olein, extra virgin olive oil, and sunflower oil were investigated. The oils were stored in three conditions, 23°C (with light and without light) and 35°C (without light). Results showed that the retention percentages of phytonutrients where in the range of 0%–100% for vitamin E, 51.24%–83.63% for carotenoid, 83.40%–100% for phytosterols and 27.94%–100% for squalene. Pearson correlation analysis between phytonutrients and oil quality of oils in different storage conditions showed that correlation coefficient values (r) were in the range of −1 to 0 for FFA, −1 to 0.22 for PV, −1 to 0.33 for AV, and −0.23 to 1 for OSI, implying that correlations between both variables are not in same direction. Degradation studies of phytonutrients using zero-order kinetic model where optimum-case conditions exhibited highest half-life (t_1/2) among the three conditions. In conclusion, storage conditions and synergistic effect affected the phytonutrients stability in the oils and oil quality in different extent. In general, storage at ambient temperature and dark condition contributed to the best phytonutrients retention and oil quality.     

Oxidative Rancidity in Refined Sunflower Oil with Respect to Storage Variation

Refined sunflower oil was stored in brown and colorless glass bottles at ambient temperature (18–32°C) and 37°C to assess the effect of light, heat and air on the stability fo the oil and to record the progress of oxidative rancidity especially the secondary stages with respect to storage variation and time. Oil sample stored in brown color bottle was found to be superior (FFA 0.15 to 0.53; PV 0.5 to 80; HV 3 to 12; oxirane oxygen 0.2 to 2.3) over oil stored in colorless bottle (FFA 0.15 to 0.60; PV 0.5 to 91; HV 3 to 8; oxirane oxygen 0.1 to 2.8) at ambient temperature. Samples stored at 37°C deteriorated very fast. Silver nitrate test, oxidised fatty acid formation, urea adduct formation, picric acid-TLC test, Kreis test, DNP-TLC test, DNP-precipitation test have been devised to detect and follow oxidative rancidity. These tests worked well even at the lower levels of oxycompounds. No conjugation was detected in any of the oil.     

Studies on moisture sorption in coir fibers (cocos nucifera L)

Moisture desorption characteristics in coir fibers have been studied at several temperatures (53°C, 68°C, 86°C, and 105°C) as a function of time. Moisture absorption at room temperature after heating to 53°C, 68°C, 86°C, and 105°C are also reported. The results indicate that the relation between percentage moisture loss (A) (moisture loss is the ratio of the difference between initial moisture and final moisture to initial moisture) and temperature (T°K) is of the type A = A_oe^?B/T in the range of intervals studied. The constants A_o and B are dependent on time, and they decrease with time. The fraction moisture loss/gain (w) is related to time (t) by the equation w = m/t + b₀ at all temperatures investigated. The constant m decreases with temperature while b₀ increases with temperature. The equilibrium moisture content (the condition reached by the sample when it no longer takes up moisture from or gives up moisture to the surrounding atmosphere) increases with increase in relative pressure and decrease in temperatures. As the moisture content in the fiber increases, the tensile strength (tenacity) decreases and the % elongation increases. The observed results are explained on the basis of structural rearrangement on heating/cooling of lignocellulosic material.     

Dietary effects of conjugated octadecatrienoic fatty acid (9 cis, 11 trans, 13 trans) levels on blood lipids and nonenzymatic in vitro lipid peroxidation in rats

The present study examined the antioxidant activity of conjugated octadecatrienoic fatty acid (9 cis, 11 trans, 13 trans-18∶3), α-eleostearic acid, of karela seed (Momordica charantia), fed to rats for 4 wk. The growth pattern of rats and the effect on plasma cholesterol and high density lipoprotein (HDL) cholesterol and peroxidation of plasma lipid, lipoprotein, eryhrocyte membrane, and liver lipid were measured. Rats were raised on diets containing sunflower oil mixed with three different levels of conjugated trienoic fatty acid (9c,11t,13t-18∶3) 0.5,2, and 10% by weight; the control group was raised with sunflower oil as dietary oil as the source of linoleic acid (9c,12c-18∶2). The growth pattern of the three experimental groups of rats showed no significant difference compared to the control group of rats, but the group with 10% 9c,11t,13t-18∶3 had slightly higher body weight than the control group of rats. Concentrations of total cholesterol, HDL-cholesterol, and non-HDL-cholesterol in plasma were similar in all four groups. Plasma lipid peroxidation was significantly lower in the case of 0.5% 9c,11t,13t-18∶3 group than the control group and the 2 and 10% 9c,11t,13t-18∶3 dietary groups as well. Lipoprotein oxidation susceptibility test with 0.5,2 and 10% 9c,11t,13t-18∶3 dietary groups was significantly less susceptible to lipoprotein peroxidation when compared with sunflower oil dietary group, and the dietary group with 0.5% 9c,11t,13t-18∶3 showed least susceptibility. There was significant lowering in erythrocyte ghost membrane lipid peroxidation in the 0.5,2, and 10% 9c,11t,13t-18∶3 dietary groups compared to the sunflower oil groups. Nonenzymatic liver tissue lipid peroxidation was significantly lower in the group of rats raised on 0.5% 9c,11t,13t-18∶3, but the groups on 2 and 10% 9c,11t,13t-18∶3 acid did not show any significant difference compared with the control group of rats.     

Effect of Temperature and Time on the Stability of Salmon Skin Oil During Storage

The effect of 45 days of storage at 25, 4, −18 and −80 °C on the quality indices; free fatty acid (FFA) content, peroxide value (PV), thiobarbituric acid reactive substances (TBARS), and changes in the fatty acid (FA) profile of crude oil recovered from salmon fish skins were evaluated at 5 day intervals using spectrophotometric and titrimetric methods. Higher temperatures and longer storage time resulted in higher quantities of oxidative products in the salmon skin oil (SSO). By day 45, SSO stored at 25 and 4 °C had 8.50 and 8.29% FFA, 32.43 and 26.33 μg malondialdehyde (MDA) eq g⁻¹ oil, and 88.19 and 64.53 mequiv peroxide kg⁻¹ oil, respectively. No significant (p > 0.05) changes in fatty acid profile were observed at all the storage temperature and time studied.     

Influence of Zataria multiflora Boiss. essential oil on oxidative stability of sunflower oil

In this study, the influence of the application of 0.025%, 0.05% and 0.075% of Zataria multiflora Boiss. essential oil (EO) on oxidative stability of sunflower oil was examined and the EO was compared to butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) during storage at 37°C and 47°C. The main components of EO were identified as carvacrol (45.6%), p‐cymene (18.1%) and thymol (16.3%). Peroxide value (PV), anisidine value (AnV) and thiobarbituric acid (TBA) value measurement in sunflower oil showed that all concentrations of EO had a lower antioxidant effect in comparison to BHA and BHT. Samples supplemented with EO concentration of 0.075% were the most stable during storage at both temperatures (p<0.05). Furthermore, Totox value, antioxidant activity (AA), stabilization factor (F) and antioxidant power (AOP) determination confirmed efficacy of this EO as antioxidant in sunflower oil. EO also was able to reduce the stable 2,2‐diphenyl‐1‐picrylhydrazyl free radical (DPPH ^. ) with a 50% inhibition concentration (IC₅₀) of 34.3 ± 0.8 µg/mL. The results indicate that EO could be used as a natural antioxidant in oils for food uses.     

Effects of ultrasound-assisted air-drying on vitamins and carotenoids of cherry tomatoes

This work examined the influence of the ultrasonic-assisted air-drying on the dehydration of cherry tomatoes (Solanum lycopersicum var. cerasiforme) and on the availability of vitamins B, E, and carotenoids in the dried product. This study allowed estimating the effective water diffusivity for the air-drying process and for the air-drying process subjected to ultrasonic waves. The water effective diffusivity increased by 33–89%, depending on the operating conditions, when subjected to ultrasound. The application of ultrasound increased the availability of vitamins B₁, B₂, B₃, B₆, and B₅, releasing the vitamins bounded to membrane, protein, or apoenzyme. The use of ultrasound allowed the retention of carotenoids in the dried product when drying was carried out at a low temperature (45°C) and low air velocities (1 m/s).     

Phase equilibria and fractionation of linear homopolymers in solution: A thermodynamic numerical interpretation

A numerical procedure is described for the quantitative interpretation of experimental fractionations by successive precipitations. The analysis is based on a thermodynamic relationship (mp″/mp′ = A·B^p) between the masses of a polymeric component with degree of polymerization, p, distributed between two liquid phases in equilibrium (mp″ and mp′) and the parameters A and B, which are independent of the degree of polymerization but functions of the thermodynamic variables. An individual pair of A and B parameters corresponds to every individual fraction. The numerical procedure, which is iterative in nature, provides the means for calculating the molecular-weight distribution of the individual fractions. The procedure requires data from the experimental fractionation (number-average degree of polymerization and total mass fraction of each fraction) and knowledge of the molecular-weight distribution function of the whole, starting polymer. The procedure was applied to the analysis of the results of two experimental fractionations of polyamide 11, whereby covergence was quickly reached after a few iterations in the calculations of every set of A and B parameters.     

Effect of moisture content of oil type sunflower seed on fungal growth and seed quality during storage

Oil-type hybrid sunflower seed exposed to relative humidities of 65%, 84% and 93% in environmental chambers at 10 C attained equilibrium moisture contents (mc) of 7.5±0.2%, 10.1±0.2% and 13.4±0.5% and were stored under these conditions for up to 60 weeks (wk). At 7.5% mc, germinability of seed changed very little during storage, but at 10.1% mc and 13.4% mc, germination significantly decreased during storage. At 7.5% mc, free fatty acid (FFA) levels in extracted oil did not change significantly during 60 wk of storage. However, at 10.1% mc, FFA increased significantly during 40 wk of storage and were significantly correlated with the invasion of seed by the storage fungusAspergillus (r=0.81) At 13.4% mc, FFA increased significantly during storage and were positively correlated with the invasion of seed byAspergillus andPenicillium and negatively correlated with germination percentage. Invasion of surface-disinfected seed by fungi decreased from 83% to ca 66% of total seed during storage at 7.5% mc. The predominant fungus wasAlternaria alternata (Fr.) Keissler. A previously unreportedAlternaria sp., morphologically similar toA. ricini (Yoshii) Hansford andA. macrospora, was isolated from 9% of the seed. At 10.1% mc, fungal invasion also decreased for 24 wk and then began increasing again. At 24 wk of storage,Aspergillus began invading the seed. At 13.4% mc, 100% of the seed were invaded with fungi within 8 wk of storage. TotalAlternaria rapidly decreased during storage: and after only 4 wk of storage, the seed were invaded by bothAspergillus andPenicillium. After 24 wk of storage, the predominant genus wasAspergillus, followed byPenicillim andAlternaria. Other fungi invading the seed wereCladosporium, Phoma, Mucor, Rhizopus and several unidentified fungi.     

Impacts of Oil Types and Storage Conditions on Milk Fat Quality of Strained Yogurt Immersed in Oil

To maintain strained yogurt freshness, it was shaped into balls (3–3.5 cm diameter), completely immersed in oil, and stored at refrigerated or ambient temperature for 6 months. The impacts of immersing strained yogurt in oil on the topped oil and product's final quality of lipids including fat oxidation, lipolysis, cholesterol oxidation, and conjugated linoleic fatty-acid content (CLNA) (i.e., as freshness indicators), during storage under various storage conditions, were evaluated. Peroxide value (PV), 7-keto-cholesterol, free fatty acids (FFA), and CLNA content were also determined. When stored in light, FFA of strained yogurt immersed in olive or corn oil increased from 0.44 to 1.29 and from 0.12 to 0.58, respectively. Olive oil-topped and corn oil-topped samples exposed to light had 48.9 and 7.9 (meq O₂ kg⁻¹) PV, respectively. Similar trends were reported for strained yogurt fat during storage for up to 6 months. Storage conditions showed little to no effects on the rate of fat and cholesterol oxidation, fat lipolysis, and CLNA content. Strained yogurt freshness indicators were maintained during the extended storage duration without refrigeration. The freshness indicators have a significant impact on enhancing consumer preference of strained yogurt.     

Extrusion deactivation of rice bran enzymes by pH modification

Rice bran is considered in Mexico as “waste”, useful only for feeds. As considerable amounts of oil are available in rice bran, it might be worthwhile to stabilize it and extract the edible oil before using it for feedstuffs. Precisely these oils are responsible for rice bran rapid deterioration, particularly in climatic conditions such as those prevalent in Mexico's tropical areas (high humidity and high temperature). This paper deals with the study of the effect of pH during extrusion of fresh rice bran in order to inactivate lipid‐breaking enzymes. Hydrochloric acid or calcium hydroxide, Ca(OH)₂, were added at 0, 1, 5, 10% (dry basis), and moisture content of the bran samples was varied (20, 30, 40%, dry basis) in a 3² factorial design to corroborate its effect at acid and alkaline pH range. Free fatty acids (FFA) increase was the control variable. Extruded samples were stored at room temperature (between 20 and 28 °C) using a non‐extruded sample as control to assess the shelf life effects. Results indicate that in acid‐extruded samples, the increase in FFA concentration after 98 days was much less than in the unmodified‐pH or alkaline samples. The lowest FFA increase after 3 months of storage time was <10 mg FFA/g rice bran using extrusion with no water or chemicals added or using extrusion adding HCl, irrespective of the moisture content of rice bran.     

Agronomic performance of high oleic,low linolenic soybean in Tennessee

Soybean oil hydrogenation alters the linolenic acid molecule to prevent the oil from becoming rancid, however, health reports have indicated trans-fat caused by hydrogenation, is not generally regarded as safe. Typical soybeans contain approximately 80 g kg⁻¹ to 120 g kg⁻¹ linolenic acid and 240 g kg⁻¹ of oleic acid. In an effort to accommodate the need for high-quality oil, the United Soybean Board introduced an industry standard for a high oleic acid greater than 750 g kg⁻¹ and linolenic acid less than 30 g kg⁻¹ oil. By combing mutations in the soybean plant at four loci, FAD2-1A and FAD2-1B, oleate desaturase genes and FAD3A and FAD3C, linoleate desaturase genes, and seed oil will not require hydrogenation to prevent oxidation and produce high-quality oil. In 2017 and 2018, a study comparing four near-isogenic lines across multiple Tennessee locations was performed to identify agronomic traits associated with mutations in FAD3A and FAD3C loci, while holding FAD2-1A and FAD2-1B constant in the mutant (high oleic) state. Soybean lines were assessed for yield and oil quality based on mutations at FAD2-1 and FAD3 loci. Variations of wild-type and mutant genotypes were compared at FAD3A and FAD3C loci. Analysis using a generalized linear mixed model in SAS 9.4, indicated no yield drag or other negative agronomic traits associated with the high oleic and low linolenic acid genotype. All four mutations of fad2-1A, fad2-1B, fad3A, and fad3C were determined as necessary to produce a soybean with the new industry standard (>750 g kg⁻¹ oleic and <30 g kg⁻¹ linolenic acid) in a maturity group-IV-Late cultivar for Tennessee growers.     

Ultrasonic attenuation of edible oils

The frequency dependence (1–60 MHz) of the ultrasonic attenuation coefficient of canola oil, corn oil, olive oil, peanut oil, safflower oil, soybean oil, and sunflower oil was measured at 25°C. The attenuation coefficient of all the oils could be described by the relation: α ∼ Af ⁿ(with A between 6 and 40 × 10⁻¹², and n between 1.74 and 1.86).     

Extraction and identification of natural antioxidant from the seeds of the Moringa oleifera tree variety of Malawi

The oil from the dried seeds of the Moringa oleifera tree (variety of Malawi) was extracted with a mixture of chloroform/methanol (50∶50). The induction period measurements demonstrated a great resistance to oxidative rancidity. After degumming, there was a reduction of 74% in induction periods. The gums produced were extracted with diethylether, n-butanol, and water, yielding four fractions: Fraction 1 (81.8% w/w), Fraction 2 (0.04% w/w), Fraction 3 (0.05% w/w), and Fraction 4 (17.0% w/w). These fractions were tested for their protection of fresh sunflower oil against rancidity, at 50°C, using a UV accelerated method. The oxidation of the sunflower oil was measured using PV; absorbance E _1cm ^1% and malondialdehyde concentration were measured by HPLC. The fraction that showed the highest antioxidant activity was further fractionated by HPLC, yielding seven fractions. Fraction HPLC 3 (present in a quantity of 330.8 and 29.11 ppm in gums and oil, respectively) showed the highest antioxidant activity. Its activity was also compared with that of the commonly used antioxidants BHT and α-tocopherol on sunflower oil using the same methods. At the same level of addition (200 ppm), HPLC 3 showed higher antioxidant activity than BHT and α-tocopherol. The identification of HPLC3 was done using ¹H NMR, ¹³C NMR, MS, melting point, and UV absorption spectroscopy and proved to be 3,5,7,3′,4′,5′-hexahydroxyflavone (myricetin).     

Extraction of Oil from Roman Nettle Seed by Cold Press and Evaluation of its Quality during Storage

Roman nettle (Urtica pilulifera L.) is an annual plant whose seeds are rich in oil and valuable phytochemicals. In this study, oil from Roman nettle seeds is extracted by cold pressing and its quality is evaluated during storage at room temperature for up to 90 days. The seed moisture content is adjusted to 0%, 2.5%, 5%, 7.5%, and 10% (g 100 g⁻¹) to evaluate its effect on oil extraction yield. The highest oil yield (31.5%) is found in the seeds containing 5% moisture. Acid and peroxide values increase with both moisture content increase and during storage. Moreover, an increase in seed moisture content decreases the oxidative stability (from 8.1 to 6.3 h), carotenoids (from 25 to 14 mg kg⁻¹), chlorophylls (from 742 to 486 mg kg⁻¹), and phenolic contents (from 134 to 97 (mg caffeic acid per kg oil)) of the extracted oils. Fatty acid profile and phytosterols are not significantly influenced (p > 0.05) by the moisture content of the seeds and storage. Total phenol contents and γ-tocopherol levels increase during storage, but carotenoids, chlorophylls, and α-tocopherol levels decrease. Based on overall composition and quality parameters, Roman nettle seed oil may have potential food applications.     

Effect of enzymatic transesterification on the melting points of palm stearin-sunflower oil mixtures

Transesterification with lipases may be used to convert mixtures of fats to plastic fats, making them more suitable for use in edible products. In our study, 1,3-specific (Aspergillus niger, Mucor javanicus, Rhizomucor miehei, Rhizopus javanicus, and Rhizopus niveus) and nonspecific (Pseudomonas sp. and Candida rugosa) lipases were used to transesterify mixtures of palm stearin and sunflower oil (PS-SO) at a 40:60 ratio in a solvent-free medium. The transesterified mixtures of PS-SO were analyzed for their percentage free fatty acids (FFA), degree and rate of transesterification, solid fat content, slip melting point (SMP), and melting characteristics by differential scanning calorimetry. Results indicated that Pseudomonas sp. lipase produced the highest degree (77.3%) and rate (50.0 h⁻¹) of transesterification, followed by R. miehei lipase at 32.7% and 27.1 h⁻¹, respectively. The highest percentage FFA liberated was also in the reaction mixtures catalyzed by Pseudomonas sp. (2.5%) lipase and R. miehei (2.4%). Pseudomonas-catalyzed mixtures produced the biggest drop in SMP (13.5°C) and showed complete melting at below body temperature. All results indicated conversion of the PS-SO mixtures to a more fluid product. The findings also suggest that the specificity of lipases may not play a significant role in lowering the melting point of the PS-SO mixtures.     

Enrichment of CLA isomers by selective esterification with l-menthol using Candida rugosa lipase

Commercially available preparations of CLA are composed of almost equal amounts of 9-cis,11-trans (9c,11t)-CLA and 10-trans,12-cis (10t,12c)-CLA. Each isomer was fractionated and enriched, for availability as a food supplement, by a process comprising selective esterification with l-menthol by Candida rugosa lipase, distillation, and n-hexane extraction. The first selective esterification of CLA isomers was conducted with an equimolar amount of l-menthol of 30°C. The oil phase of the reaction mixture was fractionated into an l-menthyl ester fraction (9c,11t-CLA rich) and an FFA fraction (10t,12c-CLA rich) by distillation. The FFA fraction was esterified again with an equimolar amount of l-menthol to enrich 10t,12c-CLA. The 10t,12c-CLA preparation was obtained as the resulting FFA fraction by distillation. 10t,12c-CLA was enriched to 91% with 40% recovery. To enrich 9c,11t-CLA, the l-menthyl ester fraction in the first esterification was chemically hydrolyzed, and the resulting FFA were esterified again with an equimolar amount of l-menthol. The 9c, 11t-CLA preparation was obtained by chemical hydrolysis of the resulting l-methyl ester fraction, followed by n-hexane extraction. 9c,11t-CLA was enriched to 94% with 42% recovery. This effective process for purification of CLA isomers using l-methol is applicable to the production of food supplements.     

Effects of Linalyl Oleate on Soybean Oil Flavor and Quality in a Frying Application

Bread pieces were fried at 180 °C in soybean oil (SBO) containing no additives (control), 0.1% linalyl oleate (LO), or 10 ppm methyl silicone (MS). After 2 h of heating, the MS-containing oil was the most stable, followed by the oil with LO and the control, based on conjugated dienoic acid percentage (CD) and the ratio of linoleate%/palmitate%. Oil extracted from the fresh fried bread showed similar, but not significant, trends for CD and PV. Fresh and stored (60 °C, 2 days) bread fried in LO-containing oil had less hexanal than the other two treatments, and the stored LO bread had less t,c- and t,t-2,4-heptadienal than the control. Fresh bread fried in LO-containing oil had a less rancid flavor than did the other two treatments, and the LO treatment had less fishy flavor than the control. In stored bread, the MS treatment was less rancid than the control. In oil extracted from the stored bread, the amounts of t,c-2,4-heptadienal and 2-decenal correlated (p ≤ 0.05) with the amounts of individual unsaturated fatty acids and with CD, but only t,c-2,4-heptadienal correlated with the PV. The t,c-2,4-heptadienal correlated with individual Polyunsaturated fatty acids (PUFA) in freshly fried bread. In general, oil and fried bread had improved flavor quality and/or oil stability when they contained MS or LO.     

The effect of mixed surfactants on enhancing oil recovery

Micelles composed of mixed surfactants with different structures (mixed micelles) are of great theoretical and industrial interest. This work pertains tomaximizing interfacial tension (IFT) reduction via surfactant pairs. In this respect, four types of fatty acid amides based on lauric, myristic, palmitic, and stearic acids were blended with dodecyl benzene sulfonic acid at a molar ratio of 4∶1 and designated as A₁, A₂, A₃, and A₄, respectively. The IFT was measured for each blend at different concentrations using Badri crude oil. The most potent formula (A₄) was evaluated for using in enhanced oil recovery (EOR). The IFT was tested in the presence of different electrolyte concentrations with different crude oils at different temperatures. Finally several runs were devoted to study the displacement of Badri crude oil by A₄ surfactant solution using different slug sizes of 10, 20, and 40% of pore volume (PV). The study reveled that Badri crude oil gave ultra-low IFT at lowest surfactant concentration and 0.5% of NaCl. The recovery factor at a slug size of 20% PV was 83% of original oil in place compared with 59% in case of conventional water flood.     

Roasted Sunflower Kernel Paste (Tahini) Stability: Storage Conditions and Particle Size Influence

Sunflower tahini faces quality problems due to the tendency of oil to exudate, causing accelerated rancidity and low marketability. In this study, the colloidal and oxidative stability of different trimodal particle size distributions of sunflower tahini (cumulative volume percentages of small, middle and large class populations of 9.61–16.67, 43.03–55.03 and 47.36–28.3) was evaluated during storage at three different temperatures. Decreasing sample particle size decreased the sunflower tahini colloidal stability. The coarsest prototype, being the most stable tahini in terms of oil separation, was included in the oxidative stability storage test together with a commercial tahini. The peroxide values of the studied sunflower tahini samples increased significantly (p < 0.05) with storage time, irrespective of storage temperature, while the p‐anisidine values showed an irregular pattern. Considering 30‐meq O₂/kg as a PV limit, the commercial tahini showed good oxidative stability as it was under this when stored 3 months at 4 °C, 2 months at room temperature and 1 month at 40 °C. The coarsest tahini sample was under the limit when stored 2 months at 4 °C, 1 month at room temperature and 2 weeks at 40 °C. Particle size was shown to be an essential parameter for controlling sunflower tahini's overall stability.