Assessment of rheological, qualitative and antioxidant characteristics of enriched peanut butter with date paste through shelf-life stability

Over the years, concentrated efforts have been directed toward the improvement of desirable characteristics and attributes in peanut butter. This study examined the effect of rheological, antioxidant and qualitative characteristics of optimum peanut butter (including date paste and lecitin) during shelf-life. The results showed that the presence of date paste along with lecithin in optimum peanut butter improved the overall characteristics of peanut butter, including the physicochemical, microbial, mechanical, and sensory properties, compared to the control. Moreover, shelf-life had the most effect on reducing the emulsion stability, cohesiveness, antioxidant properties, and overall acceptance. In addition, the flow behavior of the emulsions was examined through the Herschel-Bulkley model using the parameters of determination coefficient, R2, flow behavior index, n, and consistency coefficient, K (Pa.sn). The presence of date paste in enriched peanut butter results in the creation of a colloidal structure among the peanut particles. This structure traps the oil, preventing it from leaving the peanut paste texture during shelf-life.

The Effects of Oil Content on the Structural and Textural Properties of Cottonseed Butter/Spread Products

Plant-based butters from nuts and seeds have steadily increased in consumer popularity due to their unique flavors and healthy nutritional properties. Oil content is a critical parameter to measure the proper consistency and stability of plant butter and spread products. Previous work has shown that glandless cottonseed can be used to formulate cottonseed butter products to increase the values of cottonseed. As part of the efforts made in the valorization of cottonseed, this work evaluated the effects of oil content on the microstructural and textural properties of cottonseed butter/spread products. While the oil content in the raw cottonseed kernels was 35% of the kernel biomass, additional cottonseed oil was added to make cottonseed butter products with six oil content levels (i.e., 36, 43, 47, 50, 53, and 57%). The values of three textural parameters, firmness, spreadability, and adhesiveness, decreased rapidly in an exponential mode with the increasing oil content. The particle size population in these butter samples was characterized by similar trimodal distribution, with the majority in the middle mode region with particle sizes around 4.5-10 μm. Higher oil content decreased the butter particle size slightly but increased oil separation during storage. The oxidation stability with a rapid oxygen measurement was gradually reduced from 250 min with 36% oil to 65 min with 57% oil. The results of this work provide information for the further optimization of formulation parameters of cottonseed butter products.

Assessment of Natural Waxes as Stabilizers in Peanut Butter

Manufacturers add sugar and fully hydrogenated vegetable oils to peanut butter to avoid its oil separation during storage. Unfortunately, hydrogenated oils are significant sources of saturated fats, and reducing their consumption is challenging for food scientists without affecting the desired characteristics of food products. Therefore, in a preliminary study, 1%, 1.5%, and 2% of three natural waxes (rice bran, carnauba, and beeswax) were added to the natural peanut butter to test their efficacy as a stabilizer. Rice bran and carnauba wax added to peanut butter presented a higher elastic modulus (G’) and lower oil separation percentages than beeswax. However, no significant differences were found between the different percentages of waxes. Thus, in the final experiments, 1% of these selected waxes (rice bran and carnauba waxes) were added directly to the roasted ground peanut. Due to the difficulty of adding high melting point waxes to the peanut butter, a second experiment added wax oleogel (rice-bran and carnauba wax) to defatted peanut flour. After four weeks of storage, all of the samples were examined for their texture (TPA) and oil separation. The sample with directly added bran wax had the highest values for spreadability and firmness, and the lowest oil separation, which was 11.94 ± 0.90 N·s⁻¹, 19.60 ± 0.71 N·s⁻¹, and 0.87 ± 0.05%, respectively. In the peanut flour sample, the spreadability, firmness, and separated oil of the rice bran wax oleogel added sample were 46.95 ± 0.99 N·s⁻¹, 66.61 ± 0.93 N, and 1.57 ± 0.07%, respectively. However, the textural properties of the rice bran wax oleogel added sample were close to the commercial peanut butter (natural and creamy). Therefore, the results indicate that the rice bran wax oleogel could be the potential replacement of the fully hydrogenated oil as a stabilizer.

Texture and flavor evaluation of peanut butter stabilized with natural waxes

Natural peanut butter was stabilized with 1.0%-2.0% (w/w) beeswax (BW), candelilla wax (CLW), rice bran wax (RBW), or sunflower wax (SFW). The appearance, spreadability, mouthfeel, and flavor attributes of these samples were evaluated by a trained sensory panel using commercial stabilized peanut butter and a sample stabilized with hydrogenated cottonseed oil as references. The waxes and their blend ratio significantly (p < 0.05) influenced appearance, spreadability, firmness, mouthfeel, and flavor attributes. Samples with 1.5%-2.0% CLW, or 1.0%-1.5% RBW had the fewest differences in appearance and texture from the reference and commercial samples. However, an off-flavor was attributed to 1.5% or higher CLW. Samples stabilized with BW or with 1.0%-1.5% RBW had the fewest difference in flavor compared to the reference sample. Overall, samples stabilized with 1.0%-1.5% RBW scored closest to the commercial and reference samples. The response of CLW, RBW, and SFW (which was only evaluated for appearance and spreadability) indicates that amounts of these waxes could be tailored in different products to achieve a product with desirable texture and flavor as well as stability to oil loss. PRACTICAL APPLICATION: This research provides information that could be used by food companies that make seed or nut butters as spreads or as ingredients for use in foods. It shows the impact of the use of four types of waxes as stabilizers, at commercially relevant levels (< 3.0%), and at levels previously shown to be effective for stabilization, on the firmness, spreadability, and other texture and flavor attributes, and thus provides a starting point for optimization for commercial product specifications.

Development of Seed Butter Made with Pumpkin, Sesame, and Sunflower Seeds and the Influence of Natural Antimicrobials and Stabilizers on Its Shelf Life

This study investigated the antimicrobial efficacies of grape seed extract (GSE) and cinnamaldehyde (CIN) against Salmonella enterica and Listeria innocua and the influence of hydrogenated rapeseed oil (HRO) and palm kernel oil (PKO) on the texture and oil separation in pumpkin/sesame/sunflower seed butter. The results showed that the 10 and 15% GSE significantly reduced both S. enterica and L. innocua. Cinnamaldehyde was effective against S. enterica but did not significantly reduce L. innocua. Hydrogenated rapeseed oil at 2 and 3% concentrations prevented hardening of the seed butter and thus facilitated its spreadability. The 3% HRO-stabilized seed butter had less oil separation and a better texture than the control. Although PKO influenced the hardness of the butter after 35 days, its effect was not as pronounced as that of HRO. The HRO was also more effective in reducing the adhesiveness and thus the stickiness of the seed butter when compared with the PKO. Both HRO and PKO did not influence cohesiveness and adhesiveness changes to the butter after 7 days, although the HRO samples showed a lower level of cohesiveness when initially added to the samples.

Microbial safety of oily, low water activity food products: A review

Oily, low water activity (OL a_w) products including tahini (sesame seed paste), halva (tahini halva), peanut butter, and chocolate, have been recently linked to numerous foodborne illness outbreaks and recalls. This review discusses the ingredients used and processing of OL a_w products with a view to provide greater understanding of the routes of their contamination with foodborne pathogens and factors influencing pathogen persistence in these foods. Adequate heat treatment during processing may eliminate bacterial pathogens from OL a_w foods; however, post-processing contamination commonly occurs. Once these products are contaminated, their high fat and sugar content can enhance pathogen survival for long periods. The physiological basis and survival mechanisms used by pathogens in these products are comprehensively discussed here. Foodborne outbreaks and recalls linked to OL a_w foods are summarized and it was observed that serotypes of Salmonella enterica were the predominant pathogens causing illnesses. Further, intervention strategies available to control foodborne pathogens such as thermal inactivation, use of natural antimicrobials, irradiation and hydrostatic pressure are assessed for their usefulness to achieve pathogen control and enhance the safety of OL a_w foods. Sanitation, hygienic design of manufacturing facilities, good hygienic practices, and environmental monitoring of OL a_w food industries were also discussed.

Stabilization of peanut butter by rice bran wax

To improve stability of peanut butter, rice bran wax (RBX) was added into peanut butter as a stabilizer by formation of organogel. Effects of addition of RBX, heating temperature, and cooling temperature on stabilization effect of peanut butter by RBX were investigated. The optimum conditions were as follow: addition of RBX at 4.0 wt%; heating temperature at 85 °C, and cooling temperature at 20 °C. Under the optimum conditions, the oil loss of peanut butter decreased from 12.19% to 4.04%, and the adhesiveness of peanut butter increased from 23.5 to 165.9 g·s. After storage for 25 weeks, the acid value (AV) of peanut butter prepared under the optimum conditions increased from 0.65  to 0.80 mg/g, and the peroxide value (PV) increased from 0.116 to 0.127 meq/kg. However, the AV of natural peanut butter increased to 1.73 mg/g, and PV increased to 0.178 meq/kg. The confocal laser scanning microscope images showed that the cooling temperature significantly affected crystallization of RBX and distribution of solid particles. When RBX formed needle-like crystals and peanut solid particles were evenly distributed in the oil phase, stable peanut butter was obtained. These results suggested that the RBX was an effective stabilizer for peanut butter. PRACTICAL APPLICATION: Oil separation often occurred to peanut butter during storage, which reduced the sensory quality of peanut butter and shortened its shelf life. This study stabilized peanut butter by addition of RBX based on the formation of organogel, which was of great practical significance to improve the shelf life of peanut butter.

Effect of emulsifier and viscosity on oil separation in ready-to-use therapeutic food

Oil separation is a common food quality problem in ready-to-use therapeutic food (RUTF), the shelf-stable, peanut-based food used to treat severe acute malnutrition in home settings. Our objective was to evaluate the effect on oil separation of three emulsifiers at different concentrations in RUTF. We also assessed two viscosity measurements. A scale-up experiment was carried out during full-scale RUTF production in Malawi. Results indicate that viscosity is inversely correlated with oil separation, and that the Bostwick consistometer is a simple, useful tool to predict viscosity. Oil separation in RUTF may be mitigated by use of an emulsifier, which increases the viscosity of the product. The emulsifier that reduced oil separation to the greatest extent was a mixture of high and low monoacylglycerol (MAG) emulsifiers. Proper raw material quality control to achieve consistent ingredient fat level and fat type, and production temperature and shearing control should be a focus in RUTF manufacturing.

Plant based butters

During the last few years the popularity for the plant based butters (nut and seed butters) has increased considerably. Earlier peanut butter was the only alternative to the dairy butter, but over the years development in the technologies and also the consumer awareness about the plant based butters, has led the development of myriad varieties of butters with different nuts and seeds, which are very good source of protein, fiber, essential fatty acids and other nutrients. These days' different varieties of plant based butters are available in the market viz., peanut butter, soy butter, almond butter, pistachio butter, cashew butter and sesame butter etc. The form of butter is one of the healthy way of integrating nuts and seeds in to our regular diet. Nut and seed butters are generally prepared by roasting, grinding and refrigerated to consume it when it is still fresh. During this process it is imperative to retain the nutritional properties of these nuts and seeds in order to reap the benefits of the fresh nuts and seeds in the form of butter as well. Proper care is needed to minimize the conversion of healthful components in to unhealthy components during processing and further storage. Roasting temperature, temperatures during grinding and storage are the vital factors to be considered in order to have healthy and nutritious plant based butters. In this article, different plant based butters and their processing methods have been described.

Storage stability of value added products from sunflower kernels

Shelf life of two products namely chikki and oilseed butter were evaluated. Sunflower was substituted for groundnut at three levels (0, 50 and 100 %). Products were stored up to 2 months in ambient conditions (25-30 °C; RH 40-60 %). Chikki was packed in Low density polyethylene (LDPE) and laminated pouches and oil seed butter was stored in glass and plastic jars. Products were evaluated for sensory characteristics, absence of rancidity; per cent free fatty acid and peroxide value. Stored chikki was evaluated for microbial load. Products were acceptable for sensory attributes even at the end of storage period. Product chikki stored in laminated pouches had higher per cent free fatty acid and peroxide value compared to that stored in Low density polyethylene (LDPE) pouches. Oilseed butter stored in glass jar had higher per cent free fatty acid when compared to that stored in plastic jar. Stored chikki had higher microbial load in the Low density polyethylene (LDPE) when compared to that stored in laminated pouches. Products made with groundnut alone (control) were preferred over those made in combination with sunflower and groundnut (1:1) or sunflower alone. However all products were highly acceptable at the end of storage period.