In general, there are three methods for extracting oil from various sources: mechanical, solvent, and pre-press-solvent. Each of these methods has its own advantages and disadvantages, with extraction efficiency depending on key factors such as the extraction technique, the properties of the plant component matrix, and the solvent used. Factors like temperature, pressure, and time also play a role. Researchers have consistently sought to replace or complement these methods to reduce residual oil in products. This study introduces new oil extraction methods that have gained attention in recent years, including the microwave, pulsed electric field, ultrasound, supercritical fluid, enzymatic, ohmic, and combined methods to enhance efficiency. The research demonstrates that these methods increase oil extraction efficiency and bioactive compound extraction from plant sources, resulting in improved oil quality. Most methods also reduce extraction time, offering researchers and industrialists a variety of options for their oil extraction needs. However, the study notes contradictions in the results, such as varying acidity levels in the oil, which may be attributed to raw materials and study conditions. In the end, it was determined that ultrasound, pulsed electric field, and enzyme methods can be used industrially to extract oil from olives, while supercritical fluid can be used to extract oil from certain seeds.

The aim of this study was to investigate the chemical composition, sensory attributes, texture properties (Back extrusion test), antioxidant activity, and phenolic compounds of black plum peel jam as a function of black plum puree (40, 50, and 60%) and pectin (0, 0.1, 0.2, 0.3, and 0.4%). Instrumental texture evaluation showed that increasing the pectin level increased texture parameters (firmness, cohesiveness, consistency, and index of viscosity), nonlinearly. Sensory evaluations showed that total acceptance decreased by black plum peel puree. It seems that brighter samples received more acceptance for panelists. Black plum peel jam including 40% puree and without pectin was determined as the best formulation among the samples. Antioxidant capacity and total phenolic compounds of black plum peel jam picked up with increasing the puree concentration. PLS analysis showed that the results of sensory and instrumental properties were in agreement with each other.

This study investigated the effect of black plum peel puree (40–60%) and pectin (0.3−0.6%) concentrations on the chemical compositions, sensory attributes, rheological, and textural properties, antioxidant activity, and total phenolic compounds of black plum peel marmalade as a novel food. Increasing the black plum peel pure enhanced the acidity, apparent viscosity, textural properties, antioxidant activity, and total phenolic compounds, while reduced the flavor, color, spreadability, adhesiveness, and total acceptance. The increase of pectin led to a rise in apparent viscosity, firmness, and consistency of instrumental method and decreased antioxidant activity, spreadability, and color scores. The sample with 50% black plum peel puree and 0.4% pectin had the highest acceptability. It was found that black plum peel marmalade behaved as a pseudo-plastic fluid. The power-law model was found to be the most appropriate to fit the flow curves of black plum peel marmalade. Overall, the black plum peel can be suitable as a raw material for marmalade production.

Black plum peel is the by-product of plum processing and is a valuable source of antioxidants and phenolic compounds. In this research, total phenolic compounds, total flavonoid content and antioxidant activity of black plum peel were measured. After that, black plum peel extract (in concentrations 0, 400, 800, 1200 and 2000 ppm) as a natural antioxidant for improving the stability of soybean and sunflower oil was used. The oxidative stability parameters of oils (peroxide value, free fatty acids, thiobarbituric acid, conjugated dienes, and carbonyl value) were measured at 60 °C for 4–16 days. Antioxidant activity, total phenolic compounds and total flavonoid content of black plum peel were 86.87% and 100.53 mg GA /g and 871.062 mg Quercetin/g respectively. Black plum peel extract could have a significant positive effect (P<0.05) on improvement of the quality and stability parameters of soybean oil and sunflower oil. The oxidative stability parameters for commercial oils and samples containing black plum peel extract were near each other and in an acceptable range. So, black plum peel is recommended as an oxidative stabilizer of oils and alternative synthetic antioxidants.

• The effect of different type and spice percentage on the physicochemical and consumer preferences of sunflower seed investigated. • Samples had moderate consumers’ total acceptance. • PLS analysis showed the results of consumer preferences and instrumental properties were in agreement with each other.