Application of cavitation system to accelerate aqueous enzymatic extraction of seed oil from Cucurbita pepo L. and evaluation of hypoglycemic effect

Pumpkin seed oil: a comprehensive review of extraction methods, nutritional constituents, and health benefits

Pumpkin seed oil (PSO), a rich source of nutrients, is extracted from the seeds of different pumpkin varieties for food and medicines. This article aims to provide an evidence-based review of the literature and to explore the extraction technologies, nutritional properties, and biological activity of PSO. From previous literature, PSO contains a large proportion of unsaturated fatty acids, with linoleic acid as the main component, and an amount of tocopherol, phytosterol, and phenolic acids. Some differences in the yield, composition, and physicochemical properties of PSO can be associated with the pumpkin's cultivars and the extraction methods. Some novel technologies involved in supercritical fluid extraction, enzyme-assisted aqueous extraction, and ultrasound-assisted extraction have been replacing the conventional technologies gradually as promising methods for the safe, non-polluting, and effective recovery of PSO. This healthy vegetable oil was reported by several in vitro and in vivo studies to have potential protective roles in oxidative stress, inflammation, cancer, and cardiovascular diseases. © 2023 Society of Chemical Industry.

Synthesis of dietary lipids from pumpkin (Cucurbita pepo. L) oil obtained by enzymatic extraction: a sustainable approach

This study aimed to assess the nutritional properties of dietary lipids obtained through the modification of aqueous enzymatically extracted pumpkin seed (Cucurbita pepo. L) oil. The optimal growth conditions for producing pectinase using strain Aspergillus sp. 391 were determined, and partial characterization of pectinase and commercial cellulase was conducted. The enzymatic extraction was performed at pH 4.0, 50 °C, for 24 h, using a combination of pectinase and cellulase for optimum effectiveness. The crude oil obtained was analyzed for acid, peroxide, and fatty acid composition. The study found a high amount of unsaturated fatty acids, mainly linoleic acid (C18:2), and a 59% oil recovery rate. Subsequently, this oil was subjected to enzymatic acidolysis with capric acid in solvent-free media, catalyzed by lipase Lipozyme RM IM®, resulting in a product with a higher incorporation degree (48.39 ± 0.5 mol%), observed after 24 h at 60 °C using molar ratio oil:acid capric of 1:9 (run 4). The nutritional properties of this oil were improved.

A Novel Strategy for the Demulsification of Peanut Oil Body by Caproic Acid

The aqueous enzymatic method is a form of green oil extraction technology with limited industrial application, owing to the need for the demulsification of the oil body intermediate product. Existing demulsification methods have problems, including low demulsification rates and high costs, such that new methods are needed. The free fatty acids produced by lipid hydrolysis can affect the stability of peanut oil body (POB) at a certain concentration. After screening even-carbon fatty acids with carbon chain lengths below ten, caproic acid was selected for the demulsification of POB using response surface methodology and a Box-Behnken design. Under the optimal conditions (caproic acid concentration, 0.22%; solid-to-liquid ratio, 1:4.7 (w/v); time, 61 min; and temperature, 79 °C), a demulsification rate of 97.87% was achieved. Caproic acid not only adjusted the reaction system pH to cause the aggregation of the POB interfacial proteins, but also decreased the interfacial tension and viscoelasticity of the interfacial film with an increasing caproic acid concentration to realize POB demulsification. Compared to pressed oil and soxhlet-extracted oil, the acid value and peroxide value of the caproic acid demulsified oil were increased, while the unsaturated fatty acid content and oxidation induction time were decreased. However, the tocopherol and tocotrienol contents were higher than those of the soxhlet-extracted oil. This study provides a new method for the demulsification of POB.

New research development on trans fatty acids in food: Biological effects, analytical methods, formation mechanism, and mitigating measures

The trans fatty acids (TFAs) in food are mainly generated from the ruminant animals (meat and milk) and processed oil or oil products. Excessive intake of TFAs (>1% of total energy intake) caused more than 500,000 deaths from coronary heart disease and increased heart disease risk by 21% and mortality by 28% around the world annually, which will be eliminated in industrially-produced trans fat from the global food supply by 2023. Herein, we aim to provide a comprehensive overview of the biological effects, analytical methods, formation and mitigation measures of TFAs in food. Especially, the research progress on the rapid, easy-to-use, and newly validated analytical methods, new formation mechanism, kinetics, possible mitigation mechanism, and new or improved mitigation measures are highlighted. We also offer perspectives on the challenges, opportunities, and new directions for future development, which will contribute to the advances in TFAs research.

An advanced aqueous method of recovering pumpkin seed kernel oils and de-oiled meal: Optimization and comparison with other methods

The optimal process conditions of the advanced aqueous method for recovering oil and de-oiled meal from pumpkin seed kernels were: baking the kernels at 110 °C for 1 min, grinding them to pass through a sieve of 150 μm pore size, adding 1.60 ml brine to 10.00 g ground kernels, stirring for 30 min at 30 °C, centrifuging at 4000 r/min for 30 min and cold-pressing the residue from centrifugation. This method recovered > 94% oil. Its oil recovery rate was comparable to that of solvent extraction and higher than that of enzyme-assisted aqueous method or hot-pressing. It recovered edible oil with higher quality and level of coenzyme Q10, tocopherols, carotenoids, total phytosterols and squalene as compared to solvent extraction or hot-pressing and requirements of China’s national standard. It is superior to enzyme-assisted aqueous method or hot-pressing for recovering de-oiled meal which is suitable for making texturized protein.

Evaluation of Fatty Acid Compositions, Antioxidant, and Pharmacological Activities of Pumpkin (Cucurbita moschata) Seed Oil from Aqueous Enzymatic Extraction

Pumpkin seed oil is a by-product, abundant in nutrients and bioactive components that promote several health benefits. This study aimed to compare chemical compositions, antioxidant, and pharmacological activities of pumpkin seed oils extracted from Cucurbita moschata Duch. Ex Poir. (PSO1) and Cucurbita moschata (Japanese pumpkin) (PSO2) by aqueous enzymatic extraction. An enzyme mixture consisting of pectinase, cellulase, and protease (1:1:1) was used in the enzymatic extraction process. Fatty acid composition of the oils was determined using fatty acid methyl ester/gas chromatographic-mass spectrometry. Antioxidant activity assays were measured by using stable free radical diphenylpicrylhydrazyl, radical cation 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate, ferric reducing/antioxidant power, and ferric thiocyanate assay. Inhibition of enzymes involving skin aging and whitening process was investigated. Linoleic acid was a major component of all pumpkin seed oils. Additionally, there was also a significant amount of oleic acid, palmitic acid, and stearic acid detected. PSO2 possessed the highest antioxidant activities compared to PSO1 and commercial pumpkin seed oils (COM1 and COM2). Both PSO1 and PSO2 exhibited higher inhibitory effects on hyaluronidase, collagenase, and tyrosinase than the commercials. Therefore, aqueous enzymatic extraction could yield pumpkin seed oils with higher antioxidant, anti-aging, and whitening activities. This is beneficial for further pharmacological studies and can be used as a functional food for skin benefits.

Aqueous Extraction of Seed Oil from Mamey Sapote (Pouteria sapota) after Viscozyme L Treatment

In this study, aqueous enzymatic extraction (AEE) was evaluated during the process of obtaining oil from mamey sapote seed (OMSS). Viscozyme L enzyme complex was used at pH 4 and 50 °C during the optimization of the extraction process by central composite design and response surface methodology. Optimal conditions were: 3.5% (w/w) of enzyme (regarding the seed weight), 5.5 h of incubation time, 235 rpm of agitation rate, and 1:3.5 of solid-to-liquid ratio. These conditions enabled us to obtain an OMSS yield of 66%. No statistically significant differences were found in the fatty acid profile and physicochemical properties, such as the acid and iodine values and the percentage of free fatty acids, between the oil obtained by AEE or by the conventional solvent extraction (SE). However, the oxidative stability of the oil obtained by AEE (11 h) was higher than that obtained by SE (9.33 h), therefore, AEE, in addition to being an environmentally friendly method, produces a superior quality oil in terms of oxidative stability. Finally, the high oil content in mamey sapote seed, and the high percentage of oleic acid (around 50% of the total fatty acid) found in this oil, make it a useful edible vegetable oil.

Oil extraction from tiger nut (Cyperus esculentus L.) using the combination of microwave-ultrasonic assisted aqueous enzymatic method - design, optimization and quality evaluation

Microwave-ultrasonic assisted aqueous enzymatic extraction (MUAAEE) was applied to extract tiger nut oil (TNO). The conditions of MUAAEE were optimized by Plackett-Burman design followed Box-Behnken design. An oil recovery of 85.23% was achieved under optimum conditions of a 2% concentration of mixed enzyme including cellulase, pectinase and hemicellulase (1/1/1, w/w/w), particle size <600 μm, microwave power 300 W, ultrasonic power 460 W, radiation temperature 40 °C, time 30 min, enzymolysis temperature 45 °C, pH 4.9, liquid-to-solid ratio 10 mL/g and time 180 min. Oil by MUAAEE revealed the similar fatty acid compositions, triglyceride compositions, thermal behaviour and flavour compared with oil by Soxhlet extraction (SE), while the oil quality of MUAAEE is superior to that of SE. Scanning electron microscopy revealed that structural disruption of tiger nut caused by MUAAEE facilitated the oil extraction. Results suggest that MUAAEE could be an efficient and environment-friendly method for extraction of TNO.

Development of a novel fermented pumpkin-based beverage inoculated with water kefir grains: a response surface methodology approach

Pumpkin (Cucurbita pepo) is well known for its health and nutritional benefits and is recommended for daily consumption. This is the first report on optimization and development of fermented pumpkin-based water kefir beverage. Optimum pumpkin puree and brown sugar concentrations were found at 22.28 and 9.07% w/v, respectively, were made into a pumpkin-based beverage and fermented with water kefir grains for 24 h at 32 °C. The optimized fermented pumpkin-based water kefir beverage was found to be non-alcoholic, achieved good overall acceptability and high Lactobacillus, acetic acid bacteria and yeast cell viability of approximately 1012, 109 and 109 CFU mL-1, respectively. Overall, the optimized product attained superb technological characteristics and has the potential for industrial exploitation as a refreshing water kefir drink.

Comparative investigation for hypoglycemic effects of polysaccharides from four substitutes of Lonicera japonica in Chinese medicine

The polysaccharide fractions were obtained from flower buds of the four substitutes of Lonicera japonica, L. macranthoides (LMPB), L. hypoglauca (LHPB), L. fulvotomentosa (LFPB) and L. confuse (LCPB), and their hypoglycemic effects were investigated. In study, streptozocin (STZ)-induced diabetic rats were orally administrated once daily with LMPB, LHPB, LFPB and LCPB (each 800 mg/kg) for 42 days. Reduction for food and water intake (p < 0.05, p < 0.01) and levels of sugar and insulin (p < 0.01, p < 0.05) in blood, as well as elevation for contents of liver and skeletal muscle glycogen (p < 0.05) and concentrations of hepatic pyruvate kinase and hexokinase (p < 0.01, p < 0.05) were observed. Together with significant decline of total cholesterol (TC, 45.8 51.0%, p < 0.05), total triglyceride (TG, 50.6-53.8%, p < 0.01), low-density lipoprotein-cholesterin (LDL-C, 71.2-76.3%, p < 0.01) and very-low-density lipoprotein-cholesterin (VLDL-C, 45.2-50.0%, p < 0.01), the significant rise of high-density lipoprotein-cholesterin (HDL-C, 21.6-24.3%, p < 0.05) were also demonstrated. Consequently, the four polysaccharide fractions displayed notable hypoglycemic effects, similar to that of the polysaccharide fraction from L. japonica (LJP), so that they can be also considered as ingredients of functional foods for type-2 diabetes mellitus (T2DM).

Study of ultrasonic cavitation during extraction of the peanut oil at varying frequencies

The ultrasonic extraction of oils is a typical physical processing technology. The extraction process was monitored from the standpoint of the oil quality and efficiency of oil extraction. In this study, the ultrasonic cavitation fields were measured by polyvinylidene fluoride (PVDF) sensor. Waveform of ultrasonic cavitation fields was gained and analyzed. The extraction yield and oxidation properties were compared. The relationship between the fields and cavitation oxidation was established. Numerical calculation of oscillation cycle was done for the cavitation bubbles. Results showed that the resonance frequency, f_r, of the oil extraction was 40kHz. At f_r, the voltage amplitude was the highest; the time was the shortest as reaching the amplitude of the waveform. Accordingly, the cavitation effect worked most rapidly, resulting in the strongest cavitation intensity. The extraction yield and oxidation properties were closely related to the cavitation effect. It controlled the cavitation oxidation effectively from the viewpoint of chemical and physical aspects.