Optimization of conditions for producing high‐quality oil and de‐oiled meal from almond seeds by water

Abstract

Concerns over environment, safety, and cost encourage the development of an aqueous process to extract almonds oils. A new method of processing almonds using a small amount of water was established, which recovered 96.32% of oils from the almond seeds with 55.47% crude oil content. The oil produced had 0.12 mg KOH/g acid value and 1.50 mmol/kg peroxide value. The residual oil content in de‐oiled almond meal was 4.38%. No waste water was produced during the aqueous extraction of oils, and the method has a higher recovery rate of oils as compared with high‐temperature pressing and solvent extraction in terms of producing first‐class edible oils. The method developed from this study produced high‐quality de‐oiled meal that could be used for edible purposes without further refinement. Practical applications The established method has the potential of replacing solvent extraction and high‐temperature expressing for extracting almond seed oils. The findings of this study should be useful for guiding the future development of research and practice of almond seeds processing on a commercial scale.

Almond oil: A comprehensive review of chemical composition, extraction methods, preservation conditions, potential health benefits, and safety

“…Also, omega‐6 fatty acid content, peroxide and acid values, total tocopherol contents, and antioxidant activity of the oil obtained by aqueous extraction were similar to those of the oil extracted by cold‐pressing and much superior to those of the oil obtained by hexane Soxhlet method (Moghadas & Rezaei, 2017). Moreover, at pilot scale, Fu and Wu (2019) using a small amount of water (optimum almond seed kernel slurry/water ratio, 100/14) reported a higher oil recovery rate and high quality with no need for refining compared to high‐temperature pressing, solvent extraction, and traditional aqueous extraction. Interestingly, this new aqueous method does not produce wastewater during the extraction, which has a strong potential for application on a large industrial scale.…”

Extraction Methods of Oils and Phytochemicals from Seeds and Their Environmental and Economic Impacts

“…Pre-treatments are commonly applied prior to aqueous extractions, and all have the same goal of breaking down/softening the seed matrix to increase oil recovery. Regardless of the matrix, AEP usually has lower yields than the ones obtained with organic solvents; however, some research studies have shown competitive recovery yields up to 96% [61,62]. Pre-treatments are commonly applied prior to aqueous extractions, and all have the same goal of breaking down/softening the seed matrix to increase oil recovery.…”

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

“…Recently, an advanced aqueous method (AAM) has been developed for efficiently processing tea seeds (Lv and Wu, 2019a), almonds (Fu and Wu, 2019), white sesame (Lv and Wu, 2020), soybeans (Tu and Wu, 2019a), rapeseeds (Lv and Wu, 2019b), sunflower seeds, peanuts, or walnuts (Tu et al, 2017;Tu and Wu, 2019b), respectively. A comparison of optimized process conditions of the advanced aqueous method for different oilseeds is shown in Table 1.…”