Functionality of Palm Oil as a Stabilizer in Peanut Butter

ABSTRACT: Studies have shown that palm oil is an effective stabilizer in peanut butter. The objective of our investigation was to better define the role of palm oil as a stabilizer. Peanut butters without and with palm oil added at concentrations of 1.5, 2.0, and 2.5% (w/w of peanuts), and Fix-X™ (hydrogenated rapeseed and cottonseed oils as commercial control) were stored at 0, 21, 30, and 45 °C for 23 wk. Palm oil improved the oil holding capacity (OHC) of peanut butters, but had no effect on their adhesiveness and hardness characteristics. The unstabilized and palm oil-stabilized peanut butters were not as good as the Fix-X™ stabilized peanut butters with regard to their OHC, hardness, and adhesiveness characteristics.     

Unhydrogenated Palm Oil as a Stabilizer for Peanut Butter

Response surface methodology was used to investigate the potential of unhydrogenated palm oil (PO), with and without peanut shell flour (PSF), to prevent oil separation in peanut butter. Percent oil separation, texture and color attributes were measured after 0, 1 and 2 wk storage at 15, 25 and 35°C. Computer-generated contour plots indicated that 2.0–2.5% PO should effectively stabilize peanut butter stored at 21–24°C for ≥ 1 year without affecting color. PSF (≥ 0.8%) decreased L value of color by a 5% but did not increase firmness of experimental products containing PO. Samples stabilized with PO were softer than those containing a commercial stabilizer.     

MICROSTRUCTURE of PEANUT BUTTER STABILIZED WITH PALM OIL

Free oil separation is a problem in "natural" peanut butter. Studies have indicated that palm oil functions as an effective stabilizer in peanut butter. This study was undertaken to determine the effect of palm oil on microstructural features of peanut butter. Samples containing 0, 1.5 and 2.5% palm oil and a control containing hydrogenated vegetable oils were prepared and stored at 0C and 45C for 130 days. Microstructure was examined by light microscopy. Addition of palm oil in peanut butter markedly increased spatial distribution of protein bodies and cell wall fragments when compared to nonstabilized products. Palm oil has potential as a stabilizer in peanut butter, but shelf-life stability is likely to be less than that achieved with presently used stabilizers, at elevated temperatures due to a less stable microstructure resulting in a lower level of solid dispersion in the continuous oil phase.     

Oil Migration in Chocolate–Peanut Butter Paste Confectionery as a Function of Chocolate Formulation

ABSTRACT:  Migration of oil from high oil content filling to the chocolate coating can result in undesirable quality changes in filled chocolate confectionery products. The objective of this study was to monitor and model peanut oil migration in a 2-layer chocolate–peanut butter paste model confectionery. Spatial and temporal oil content changes were evaluated using magnetic resonance imaging. Five formulations of chocolate, which varied in chocolate particle size, milk fat content, and emulsifier level, were assessed at 2 temperatures, 20 and 30 °C. The spatial and temporal experimental data were modeled using a Fickian-based diffusion model, fitting for the diffusion coefficient, D , over a time frame of 17 d. Values of the diffusion coefficient ranged from 1.82 to 3.23 × 10⁻¹¹ m²/s for the chocolate formulations stored at 30 °C. No significant mass transfer took place in the 20 °C samples over the experimental time frame. This study describes the dynamic nature of the interface between the chocolate and peanut butter paste layers, quantifies the mass transfer from the peanut butter paste to the chocolate, and reinforces the importance of temperature control.     

Fate of Salmonella Tennessee in peanut butter at 4 and 22 degrees C

ABSTRACT:  This study was undertaken to determine survival characteristics of inocula of a 3-strain mixture of Salmonella Tennessee in 5 commercial brands of peanut butter (A, B, C, D, and E). Inoculated peanut butter was stored at 4 (refrigerator temperature) and 22 °C (room temperature) for up to 14 d. After 1, 3, 5, 7, and 14 d, surviving cells, including injured cells, were enumerated on appropriate selective agar, including use of the agar overlay method. Populations in samples inoculated with 10^6–7 CFU/g and stored for 14 d at 4 and 22 °C decreased by 0.15 to 0.65 and 0.34 to 1.29 log CFU/g, respectively, depending on the formulation. Peanut butter A showed a significantly lower number of S . Tennessee cells when stored at 22 °C for 14 d, compared to 4 °C ( P < 0.05). However, there was no significant difference between the levels of S. Tennessee at 4 and 22 °C in products B, C, D, and E ( P > 0.05).     

Relative Effects of Ingredients on Cake Staling Based on an Accelerated Shelf-life Test

An accelerated shelf-life test was developed to estimate the texture of devil's food cake stored 21 d at 21 °C, by studying the effects of packaging film water permeability and storage temperature over time. Best results were obtained after 7 d at 34 °C with low water permeability films. The test was used to determine the effects of 28 ingredient combinations on the incidence of cake staling. Staling was greatly reduced by partly replacing shortening with butter and glucose with sucrose. To a lesser extent, replacement of natural cocoa with dutched cocoa and use of high concentrations of fats, sugars, egg whites, or sodium bicarbonate also slowed staling rate.     

Oil Migration in 2-Component Confectionery Systems

ABSTRACT:  Oil migration from high oil content centers into chocolate coatings results in product quality changes. The objective of this study was to monitor and model peanut oil migration in 2-layer systems of increasing phase complexity. Three 2-layer systems were prepared: peanut oil/cocoa butter; peanut butter paste/cocoa butter; and peanut butter paste/chocolate. Magnetic resonance imaging was used to measure liquid oil signal as a function of position over a storage time of 193 days at 25 °C. The 3 types of samples exhibited appreciably different patterns of oil migration. The peanut oil/cocoa butter samples had mass transfer typical of oil being absorbed into a liquid/solid region. The peanut butter paste/cocoa butter magnetic resonance profiles were characterized by mass transfer with a partition coefficient greater than unity. The peanut butter paste/chocolate samples exhibited a time-dependent peanut oil concentration at the interface between the chocolate and peanut butter paste. The spatial and temporal experimental data of the peanut butter paste/chocolate samples were modeled using a Fickian diffusion model, fitting for the effective diffusivity. Values of the diffusivity for the 6 chocolate formulations ranged from 1.10 to 2.01 × 10⁻¹³ m²/s, with no statistically significant differences.     

Minimal effects of high-pressure treatment on Salmonella enterica serovar Typhimurium inoculated into peanut butter and peanut products

About 1.2 billion pounds of peanut butter are consumed annually in the United States. In 2008 to 2009, an outbreak involving Salmonella Typhimurium in peanut butter led to a recall of over 3900 products by over 200 companies. More than 700 people became sick, 100 were hospitalized, and 9 people died from this outbreak. This study examines the efficacy of high-pressure processing (HPP) to decrease S. Typhimurium American Type Culture Collection (ATCC) 53647 inoculated into peanut butter and model systems. The viability of S. Typhimurium in peanut butter stored at room temperature was investigated. A culture of S. Typhimurium (6.88 log CFU/g) was inoculated into peanut butter. Following 28 d at 20 °C there was a 1.23-log reduction. Approximately 10(6) to 10(7) CFU/g S. Typhimurium were inoculated into 4 brands of peanut butter, 3 natural peanut butters and peanut flour slurries at 2, 5, and 10% peanut flour protein in peanut oil and in distilled water. All were treated at 600 MPa for 5 min at 45 °C. While significant differences were found between natural peanut butter and peanut protein mixtures, the reduction was <1.0 log. The peanut flour/oil mixtures had a 1.7, 1.6, and 1.0-log reduction from HPP (2, 5, and 10% protein, respectively) whereas peanut flour/water mixtures had a 6.7-log reduction for all protein levels. Oil had a protective effect indicating HPP may not help the microbial safety of water-in-oil food emulsions including peanut butter. Practical Application: There have been multiple outbreaks of foodborne illness involving peanut butter products. This study looks at the potential use of high-pressure processing to reduce the bacteria that may be in peanut butter.     

Storage stability of butter oils produced from sheep’s non-pasteurized and pasteurized milk

The physical and chemical characteristics and thermal stability of butter oil produced from non-pasteurized and pasteurized sheep’s milk were studied. Thermal stability of samples was estimated by using the accelerated shelf-life testing method. Samples were stored at 60, 70 and 80 °C in the dark and the reaction was monitored by measuring peroxide, thiobarbituric acid and free fatty acid values. The peroxide and thiobarbituric acid values increased as the temperature increased. The increase of acid values of the two samples was not significant. A slight increase in free fatty acid value showed that hydrolytic reactions were not responsible for the deterioration of butter oil samples in thermal stability studies. When compared, butter oil produced from pasteurized sheep’s milk has higher thermal stability than butter oil produced from non-pasteurized sheep’s milk. Although butter oil produced from non-pasteurized milk was not exposed to any heat treatment, the shelf-life of this product was lower than the shelf-life of butter oil produced from pasteurized sheep’s milk. Therefore, heat treatment for pasteurization did not affect the thermal stability of butter oil.     

Diffusion, counter-diffusion and lipid phase changes occurring during oil migration in model confectionery systems

This study investigated the diffusion of peanut oil and counter-diffusion of cocoa butter when cylindrical tempered or untempered samples, composed of cocoa butter with or without addition of cocoa powder, were suspended in peanut oil and stored at 23 °C. Oil migration kinetics was monitored using a novel pipette technique while diffusion and counter-diffusion were measured using gas chromatography. Tempering significantly lowered (p < 0.05) the peanut oil diffusion in the samples but did not influence the counter-diffusion of cocoa butter in peanut oil. Addition of cocoa powder at a volume fraction of 0.45 significantly increased (p < 0.05) peanut oil diffusion and decreased counter-diffusion. Due to the ingress of peanut oil, the solid fat content of tempered and untempered cocoa butter samples dropped from 75% to 59% after 7 weeks and resulted in corresponding dimensional changes in the samples which were also measured using image analysis. Diffusion, counter-diffusion and lipid phase changes were combined to develop a mass balance model to predict the volume changes occurring during oil migration.     

DHA藻油在花生油中的应用研究

研究了添加0.2％、0.7％、16％、20％ DHA(来源于DHA藻油,DHA含量按35％计)净含量的花生油的保质期;考察了20％ DHA净含量的花生油在低温烹调条件下DHA的稳定性以及感官品评.实验结果表明:添加DHA藻油的花生油在62℃条件下放置28d后,过氧化值仍在国标规定的范围内,且未出现哈败及藻味;与未加热的...     

Factors Influencing the Production and Activity of a Streptococcus thermophilus Lipase

The cells from 32 strains were disrupted by pressure. All the strains except two showed lipase activity. Optimum temperature for lipase production was 44°C. Production of lipase was inhibited by addition of butter oil (29%), milk (41%) and casein (12%) and stimulated by soybean oil (39%), cream (27%) and corn oil (21%) to the medium. The enzyme was stable when stored at 37°C and 45°C for 1 wk. The enzyme was partially inactivated by pasteurization treatment (65°C/30 min). Optimum temperature and pH for lipase activity was 45°C and 9.0, respectively. The enzyme was relatively more active toward tributryin than toward natural lipids.     

Chemical and sensory changes in haddock and herring stored under modified atmosphere

The effectiveness of storage in atmospheres with increased proportions of CO₂ to extend the shelf-life of haddock and herring was examined. Using a 40: 30: 30/CO₂: O₂: N₂ atmosphere with haddock no useful extension of shelf-life was achieved at +5°C and only limited extension at 0°C. A more useful extension of shelf-life at 0°C was obtained by storing haddock in a 60: 20: 2O/CO₂: O₂: N₂ atmosphere and with herring in a 60:40/CO₂::N₂: atmosphere. Total volatile bases (TVB) and hypoxanthine values (Hx) correlated with the cooked flavour. There were no significant differences in drip-loss between the modified atmosphere packaging (MAP) stored samples and the controls. Peroxide values (PV) in herring were lower in MAP stored samples. Whole haddock and whole herring were found to have a longer shelf-life when stored in MAP at 0°C than when stored as fillets.     

Comparison of the Dispersed Phase Coalescence Mechanisms in Different Tablespreads

ABSTRACT:  Temperature-induced destabilization of the dispersed phase in butter and margarine was compared by following changes in droplet size ( d _3,3), solid fat content (SFC), and fat crystal spatial organization in the 28–34 °C range. At 28 °C, both butter and margarine were stable, with similar d _3,3 values (approximately 6 μm) and droplet size distributions. As the storage temperature was raised above 30 °C, notable droplet coalescence was observed (for example, at 32 °C d _3,3 values of approximately 10 μm for butter and approximately 12 μm for margarine were obtained). Dispersed phase coalescence in butter was dominated by coagulation, with the fat crystal network-limiting droplet–droplet contact until a minimum SFC was reached (approximately 2.5%). In margarine, the rate-limiting step for coalescence was the melting of Pickering crystals present around the dispersed aqueous droplets. Unlike butter, there was no sharp change in stability at a particular temperature or critical SFC. With these differences, coalescence in butter could be modeled as a 2nd-order process and as a 1st-order process in margarine. Overall, these results demonstrated that the kinetic stability of the dispersed aqueous phase in butter and margarine depends on SFC and the spatial distribution of fat crystals within the spreads.     

STABILITY OF OIL-IN-WATER EMULSIONS. 2. Effects of Oil Phase Volume, Stability Test, Viscosity, Type of Oil and Protein Additive

SUMMARY –Stability of oil-in-water emulsions stabilized in sodium caseinate, gelatin and soy sodium proteinate was found to be increased by either an increase in the aqueous phase protein concentration (0.5–2.5%) or oil phase volume (20–50%). Both factors were significantly interrelated. Emulsions stabilized by soy sodium proteinate were generally higher in stability as compared to those stabilized by gelatin or sodium caseinate. With emulsions containing gelatin, greater stability occurred when the stability testing temperature was increased from 37–70°C and when the time interval was decreased from 24 hr to 90 min. Maximum relative viscosities of emulsions stabilized by gelatin and sodium caseinate were 2.0 and 2.5, respectively. Emulsions stabilized by soy sodium proteinate were quite viscous, with relative viscosity from 1.5–30 depending on both protein concentration and oil phase volume. Interchanging the emulsified oil among corn, soybean, safflower and peanut oils did not alter emulsion stability when examined at three concentrations of soy sodium proteinate. Changing the oil to olive oil significantly increased emulsion stability at each soy sodium proteinate level with oil phase volumes of 30, 40 and 50%.     

Fatty Acid Composition Including Trans‐Fatty Acids in Edible Oils and Fats: Probable Intake in Indian Population

Abstract: The susceptibility of trans‐fat to the human health risk prompted the Food and Agriculture Organization (FAO) and World Health Organization (WHO) to prepare regulations or compulsory claims for trans‐fatty acids (TFA) in edible oils and fats. In this study, analysis of fatty acid composition and TFA content in edible oils and fats along with the possible intake of trans‐fat in Indian population was carried out. The analysis was carried out as per the Assn. of Official Analytical Chemists (AOAC) methodology and the results were statistically analyzed. The average TFA content in nonrefined mustard and refined soybean oils exceeded by 1.16‐ to 1.64‐fold as compared to the Denmark limit of 2% TFA in fats and oils destined for human consumption. In branded/nonbranded butter and butter oil samples, average TFA limit exceeded by 4.2‐ to 9.5‐fold whereas hydrogenated vegetable oil (HVO) samples exceeded the limit by 9.8‐fold, when compared to Denmark standards. The probable TFA intake per day through different oils in Indian population were found to be less than WHO recommendation. However Punjab having highest consumption of HVO (–15 g/d) showed 1.09‐fold higher TFA intake than the WHO recommendation, which is alarming and may be one of the factors for high cardiovascular disease mortality rate that needs further elucidation. Thus there is a need to prescribe TFA limit for edible oil, butter, and butter oil in India and to reduce the already proposed TFA levels in HVO to safeguard the health of consumers. Practical Application: The probable daily intake of trans‐fatty acid (TFA) especially through hydrogenated vegetable oil (HVO) was assessed. In absence of any specification for TFA and fatty acid composition for edible oils, butter, and butter samples, a pressing need was felt to prescribe TFA limit in India. The study indicates that TFA intake through HVO consumption is higher in States like Punjab than the recommended daily intake prescribed by WHO. Hence, strategies should be adopted to either decrease the consumption of HVO or to modify the industrial processing method of HVO with less content of TFA to safeguard the health of consumers.     

紫外线辐照花生油贮藏过程中的脂肪酸组成分析

目的:紫外线辐照花生油在贮藏过程中变化情况。方法:将对照组花生油置于254 nm的紫外灯下辐照处理40 min,将紫外组和对照组花生油分别置于40、50和60 ℃的条件下加速氧化贮藏,对28 d贮藏过程中花生油的脂肪酸组成变化进行分析,通过主成分分析和相关性分析探究紫外线辐照花生油的脂肪酸组成在贮藏过程中的相互之间的关系。结果:经紫外线辐照花生油在加速氧化贮藏过程中饱和脂肪酸和单不饱和脂肪酸含量在贮藏21 d后呈迅速递增趋势,多不饱和脂肪酸在贮藏21 d后期呈迅速递减趋势,各种脂肪酸在贮藏过程中变化幅度比对照组大;温度越高,经紫外线辐照花生油各种脂肪酸组成在贮藏过程中变化幅度越大,当贮藏温度相对较低的时候,各种脂肪酸在贮藏过程中的变化不大;主成分分析和相关性分析表明,紫外线辐照花生油中亚油酸(C18:2n6)、亚麻酸(C18:3n3)与棕榈酸(C16:0)、硬脂酸(C18:0)、油酸(C18:1n9c)、花生酸(C20:0)、花生一烯酸(C20:1)、山嵛酸(C22:0)主要影响紫外组的脂肪酸组成,多不饱和脂肪酸与单不饱和脂肪酸、饱和脂肪酸存在极显著的负相关,单不饱和脂肪酸与饱和脂肪酸存在极显著的正相关。结论:紫外辐照花生油在贮藏过程中的脂肪酸组成比对照组的变化幅度大,较高的贮藏温度使紫外辐照花生油的脂肪酸组成和种类发生变化。     

Effect of Ozone on Postharvest Quality of Persimmon

ABSTRACT:  The effect of gaseous ozone exposure on the quality of persimmon picked at 2 different harvest dates was evaluated. Fruit from both harvests were continuously exposed to 0.15 ppm (vol/vol) of ozone for 30 d at 15 °C, 90% relative humidity (RH). Then, fruit were submitted to astringency removal treatment (24 h at 20 °C, 98% CO₂) and stored for 7 d at 20 °C (90% RH) in order to simulate shelf-life period. The most important disorder was flesh softening, which took place when fruit were transferred from 15 °C to shelf-life conditions. In the 2nd harvest, where the fruit were harvested with lower firmness, ozone maintained firmness over commercial limits even after 30 d at 15 °C plus shelf-life. Ozone-treated fruit showed the highest values of weight loss, coinciding with the maximum electrolyte leakage (EL) percentage. Ozone did not affect color index (CI), ethanol, total soluble solids (TSS), or pH. Unremarkable differences in acetaldehyde were observed between fruit submitted to ozone treatment and control fruit. No phytotoxic injuries in tissues were observed in ozone-treated fruit.     

Stability of Crude Herring Oil Produced from Fresh Byproducts: Influence of Temperature during Storage

ABSTRACT: Crude herring oil, extracted from fresh byproducts, was stored at 0, 20, and 50°C in order to study the effect of temperature on lipid oxidation. The oil had an initial peroxide value (PV), anisidine value (AV), and free fatty acids of 0.7 meq peroxides/kg of lipid, 0.4, and 0.6%, respectively. During storage, the oil reached the secondary oxidation stage for all 3 temperatures. The formation of fluorescent compounds was inhibited at 0°C. Significant decrease of the α-tocopherol content was found after storage at 0 and 20°C, but no consumption occurred at 50°C. The development of oxidation products over time exhibited a temperature-dependency with a very good correlation.