Optimization of ultrasound‐assisted ethanol extraction of hazelnut oil

Abstract

In this study, ethanol was used as a polar solvent to extract hazelnut oil, with ultrasound aid in the first 15 min of extraction. A Box–Behnken design was used for optimization in term of ultrasound amplitude (30%, 60%, and 90%), extraction temperature (28, 38, and 48°C), and extraction time (30, 60, and 90 min). All three factors showed positive effects on the oil extraction. The results showed that the oil yield and quality of extracted oil were significantly affected by the application of ultrasound. Ultrasound treatment had increased the oil yield from 38.93% up to 79.88%. The optimum conditions were identified at 90% of ultrasound amplitude, 29°C of extraction temperature, and 51 min of extraction time. Under these conditions, the predicted maximum oil yield was 55.39% with the minimum FFA value, iodine value and peroxide value of 1.75%, 14.52 g/100 g, and 10.50 meq g O2/kg, respectively. Practical applications Plant oil has become the first choice for edible oil due to large percentage of unsaturated fatty acid, which has been reported that it could help to reduce the bad cholesterol in human body. Hexane is the solvent that commonly used in solvent extraction stage but it is highly volatile and might cause safety issue for extraction plant. Therefore, this study aims to use ethanol to replace hexane. This research introduces the optimized ultrasound‐assisted ethanol solvent extraction process to the manufacturer. Ultrasound could enhance the oil yield which can produce low‐cost hazelnut oil to the consumer.

Effect of different extraction methods on cottonseed oil yield

“…From our results, it can be observed that after 60 min the larger EY was reached as it is demonstrated by the optimisation. This is in agreement with Wong et al (2019), who optimised the extraction of hazelnut oil via UAE, using ethanol as OS for 90 min (38 ºC and 90% of ultrasound amplitude) with an oil yield of 79.88%, an amount three-fold larger than the lowest yield reported, that corresponded to 30 min (28 ºC and 60% of ultrasound amplitude). This can be explained by the fact that longer times allow the oil contained in the sample to diffuse into the OS (de Mello et al, 2017).…”

“…Similar observations were found in the technical literature. Wong et al (2019), reported an increase in hazelnut oil extraction when temperature was raised from 28 to 38 ºC, but from 38 to 48 ºC the oil yield extraction decreased. According to our optimisation, 51 ºC was the best temperature for the extraction of CSO, which is a slightly higher value than 45 ºC, the temperature for experiment 16.…”

Pretreatment effect of osmotic dehydration on ultrasound‐assisted solvent extraction: Functional properties of defatted hazelnut meal

“…The cavitation effect which involved release of energy to surrounding can enhance the cell wall disruption and therefore increase the oil diffusion rate (O'Sullivan et al, 2016;Perrier et al, 2017). Ultrasound-assisted extraction has widely been used to extract edible oil since it is able to enhance the oil yield and shorten the extraction time (Geow et al, 2018;Wong et al, 2019).…”

Rapid screening for hazelnut oil and high‐oleic sunflower oil in extra virgin olive oil using low‐field nuclear magnetic resonance relaxometry and machine learning

“…In 1981, numerous Spaniards fell ill or died as a result of ingesting colza (rapeseed) oil denatured with aniline 4,5 . As its fatty acid composition resembles that of EVOO, hazelnut oil (HO) is often used as an adulterant 6,7 . This similarity makes it difficult to confirm the presence of HO in EVOO at low concentrations.…”