Effects of Extraction Strategies on Yield, Physicochemical and Antioxidant Properties of Pumpkin Seed Oil

A sustainable approach in pumpkin seed oil processing line: Recent advances in pumpkin seed oil and oil processing by-products

Pumpkin seed oil (PSO) has gained popularity worldwide for its nutritional profile and biological effects, significantly increasing its market demand and consumption. However, pumpkin seed oil cake (PSOC), as the secondary by-product from oil processing, contains high potential value and is scarcely utilised. With the PSO increase in production, a large amount of PSOC will be generated. The key to achieving a sustainable food system is maximising value from the food supply chain. This review aims to summarise the nutritional profile of PSO and PSOC and highlight the current advance in the biological activity of PSO and the valorisation strategies of PSOC. This review also concludes the current advance in food applications of PSO and PSOC in meat and bakery products, respectively. A better understanding of their value and current advances can help to achieve the maximisimg value from PSO processing line in an effective and sustainable approach.

Evaluation of Some Quality Parameters of Pumpkin Seeds and Oil After Roasting with Marjoram

Consumers include pumpkin seeds in their diet as a snack in raw form or minimally processed by roasting. This process enables the seeds to develop a characteristic aroma and color. Herbs and spices are also distinguished by a pleasant and delicate aroma. Among them, marjoram is particularly suited to drying, retaining its flavor better than other dried herbs. Marjoram can be used to impart flavor and aroma to food products and extend their shelf life because it can prevent lipid autoxidation. In this study, pumpkin seeds (Cucurbita pepo) were roasted with and without dried marjoram at 110 and 160 °C for 10 and 30 min, after which the oils were extracted. The results showed that with increasing temperature and roasting time, the moisture content and water activity of pumpkin seeds decreased. Furthermore, roasting pumpkin seeds with marjoram, particularly at 110 °C, enriched their aroma profile with terpenes characteristic of the marjoram aroma. Whether pumpkin seeds were roasted with or without marjoram, the fatty acid composition of the oils obtained was dominated by palmitic, stearic, oleic, and linoleic acids. However, the presence of marjoram during pumpkin seeds roasting resulted in lower peroxide values and specific extinction coefficients K232 and K270 in the oils obtained compared to their counterparts roasted without this spice. In addition, all the oils showed the ability to scavenge DPPH· radicals and were characterized by a higher proportion of yellow (positive value of the b* parameter) and green (negative value of the a* parameter) color. In comparison with the oil extracted from unroasted pumpkin seeds, the oil obtained after roasting exhibited a lower chlorophyll and a higher carotenoid content. Thus, roasting pumpkin seeds with spices may enrich their aroma profile with additional components, and the oils obtained may be characterized by better quality parameters.

Effect of Cowpea and Pumpkin Powders on the Physicofunctional Properties, Total Phenolic Content, Antioxidant Activity, and Consumer Acceptability of Soup

Cowpea (Vigna unguiculata) and pumpkin (Cucurbita maxima) play a pivotal role as affordable, nutritious food sources for humans. Low-income households can significantly benefit from supplementing their diet with nutritious and cost-effective locally available ingredients. The aim of this research was to develop a cost-effective soup formulation using ingredients that are readily available from a household garden and suitable for use in the kitchens of families with limited financial resources. The effect of cowpea and pumpkin powders on physicofunctional properties, total phenolic content (TPC), antioxidant activity (AA), and consumer acceptability of the soup were determined. Three composite soup mixes were prepared using various parts of cowpea and pumpkin at a ratio of 1:1. A control soup sample was developed, and the experimental soups were prepared by supplementing the control soup with 5%, 10%, or 15% of each composite soup mix, respectively. The physical properties, functional properties, TPC, AA, and consumer acceptability of soup were determined. The control soup had an appealing golden brown colour. Formulations 1 and 3 showed the highest relative viscosity (80.67-88.91 cP). All the experimental soup formulations had higher rehydration ratios (8-14.7 g/g) and water absorption capacities of 185.7-263.3 g/g compared to the control at 7.7 g/g and 65.7 g/g, respectively. The TPC of Formulation 2 (F2) (0.32-0.54 mg of gallic acid equivalent (GAE)/100 g powder) and Formulation 3 (F3) (0.54-0.63 mg GAE/100 g powder) was higher than Formulation 1 (F1) (0.25-0.32 mg GAE/100 g powder) and the control (0.44 mg GAE/100 g powder). Overall, the cowpea seed powder plus pumpkin fruit powder added at 10% in F2 appeared nearly optimal as a soup mix. It produced an attractive golden brown soup with increased swelling power (SP) and viscosity to assist in swallowing. Soup F1 and F2 scored high in appearance (7.27 and 7.0), aroma (7.1 and 6.7), taste (6.6 and 6.3), and overall acceptability (6.5 and 6.4). Despite having TPC and AA lower compared to F3, F2 containing 15% cowpea seed powder and pumpkin fruit has the potential to be further developed and commercialised due to the relatively high overall consumer acceptability and high acceptability in all sensory attributes.

Development and Characterization of Ethylcellulose Oleogels Based on Pumpkin Seed Oil and Rapeseed Oil

In contrast to rapeseed oil, pumpkin seed oil has yet to be well investigated in terms of oleogelation, and, to the best of our knowledge, no study related to the use of ethylcellulose (EC) in the structuring of this oil has been identified in the current scientific literature. Therefore, the present study evaluated several oleogels formulated with EC as the oleogelator in different concentrations of 7% (OG7) and 9% (OG9), based on cold-pressed pumpkin seed oil (PO) and refined rapeseed oil (RO), as well as on mixtures of the two oils in different combinations: PO:RO (3:1) (PRO) and PO:RO (1:1) (RPO). Physicochemical properties such as visual appearance, gel formation time (GFT), oil-binding capacity (OBC), oxidative and thermal stability, and textural characteristics were analyzed. Analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) were used in the statistical analysis of the data, with a significance level of p < 0.05. EC proved to be an effective structuring agent of the mentioned edible oils; the type of oils and the concentration of oleogelator significantly influenced the characteristics of the obtained oleogels. The 9% EC oleogels exhibited a more rigid structure, with a higher OBC and a reduced GFT. Pumpkin seed oil led to more stable oleogels, while the mixture of pumpkin seed oil with rapeseed oil caused a significant reduction in their mechanical properties and decreased the OBC. After 14 days of storage, all oleogels demonstrated proper oxidative stability within the bounds set by international regulations for edible fats, regardless of the kind of oil and EC concentration. All of the oleogels showed a higher oxidative stability than the oils utilized in their formulation; however, those prepared with cold-pressed pumpkin seed oil indicated a lower level of lipid oxidation among all oleogels. The P-OG9 and PR-OG9 oleogels, which mainly included PO and contained 9% EC, demonstrated the optimum levels of quality in texture, GFT, OBC, and oxidative stability.

Recent Progress on Green New Phase Extraction and Preparation of Polyphenols in Edible Oil

With the proposal of replacing toxic solvents with non-toxic solvents in the concept of green chemistry, the development and utilization of new green extraction techniques have become a research hotspot. Phenolic compounds in edible oils have good antioxidant activity, but due to their low content and complex matrix, it is difficult to achieve a high extraction rate in a green and efficient way. This paper reviews the current research status of novel extraction materials in solid-phase extraction, including carbon nanotubes, graphene and metal-organic frameworks, as well as the application of green chemical materials in liquid-phase extraction, including deep eutectic solvents, ionic liquids, supercritical fluids and supramolecular solvents. The aim is to provide a more specific reference for realizing the green and efficient extraction of polyphenolic compounds from edible oils, as well as another possibility for the future research trend of green extraction technology.