A Method for Ferulic Acid Production from Rice Bran Oil Soapstock Using a Homogenous System

Abstract

Ferulic acid (FA) is widely used as an antioxidant, e.g., as a Ultraviolet (UV) protectant in cosmetics and in various medical applications. It has been produced by the hydrolysis of γ-oryzanol found in rice bran oil soapstock. In this study, the base-catalyzed, homogenous hydrolysis of γ-oryzanol was conducted using various ratios of potassium hydroxide (KOH) to γ-oryzanol, initial concentrations of γ-oryzanol in the reaction mixture, and ratios of ethanol (EtOH) (as cosolvent)/ethyl acetate (EtOAc) (γ-oryzanol solution). Acceleration of the reaction using a planar type of ultrasound sonicator (78 and 130 kHz) at different reaction temperatures was explored. By using a heating method, the 80% yield of FA was attained at 75 • C in 4 h under homogeneous conditions (initial concentration of γ-oryzanol 12 mg/mL, the KOH/γ-oryzanol ratio (wt/wt) 10/1, and EtOH/EtOAc ratio (v/v) 5/1). With the assistance of 78 and 130 kHz irradiation, the yields reached 90%. The heating method was applied for the γ-oryzanol-containing extract prepared from rice bran oil soapstock. From soapstock, the 74.3% yield of FA was obtained, but 20% of the trans-FA in the reaction mixture was transformed into cis-form within one month.

Brønsted Acid Catalyzed Tandem Defunctionalization of Biorenewable Ferulic acid and Derivates into Bio‐Catechol

“…Esters of ferulic acid reduced the yield of catechol (2)w ith increasing chain length (methyl (8a), ethyl (8b), and propyl (8c)ester), linked to substrate solubility.C hlorogenic acid (9), involved in biosynthesis of lignin, [16] delivered 2 in 41 %y ield. Lacton esculetin (10), the main active ingredient of the traditional Chinese medicine Cortex Fraxini, [17] gave hydroxyquinol (7) with ay ield of 56 %. Other propenyl containing substrates, that is,coniferylalcohol (11), isoeugenol (12 a), eugenol (12 b), and ortho-eugenol (12 c), also cleaved with the formation of 2 in yields ranging from 42 to 65 %.…”

“…One particularly interesting biorenewable aromatic compound is ferulic acid (1a), found in plant cell walls covalently linked to (hemi)cellulose and lignin. [6] In most cases,i ti s obtained as aw aste compound of the rice industry,b y extraction from rice bran, [7] and therefore readily available on al arge scale.R ice bran derived 1a is used by Solvay to produce vanillin industrially ("Rhovanil Natural") by biocatalysis (fermentation). [8] Interestingly, 1a contains a4 -substituted catechol moiety as core structure.C atechol (2)i s amajor commodity chemical (40 kilotons year À1 )petrochemically mainly produced through hydroxylation of phenol, [5a,d] synthesized from benzene by the cumene Hock process.…”

Distributions of Polycyclic Aromatic Hydrocarbons and Phthalic Acid Esters in Gums and Soapstocks Obtained from Soybean Oil Refinery

“…Panda et al () pointed out that sunflower oil soapstock can be used as an available energy source in the diet of broiler chicken. Meanwhile, soapstock is one of the most promising candidates for bioactive molecule extraction, such as ferulic acid (Truong et al, ), γ‐oryzanol (Narayan et al, ), and gossypol (Jia et al, ), and this economical practice will help relieve environmental pollution and resource waste to a great extent.…”

“…Therefore, degumming and neutralization may decrease the contents of PAH and PAE in the soybean oils, whereas they increase their amounts in the soybean oil gums and soapstocks, reducing the safety when using them as starting materials to produce feeds and high value‐added products due to regulatory standards promulgated by countries and organizations all over the world concerning the concentrations of these harmful pollutants in food additives and other food‐related products (EFSA, ; European Commission, ). As gums and soapstocks are important by‐products that have been widely utilized in various fields (Escalera‐Valente et al, ; Pekel et al, ; Truong et al, ), the utilization of these types of wastes has given rise to certain concerns as some of them are food chain materials. However, based on our literature review, no study investigating their distributions in soybean oil gums and soapstocks has been reported.…”

Ultrasound-Assisted, Base-Catalyzed, Homogeneous Reaction for Ferulic Acid Production from γ-Oryzanol

“…FA cannot be extracted directly from their matrix in the rice bran [14] because of existence of conjugated forms and/or its ester form of c-oryzanol. However, FA can be produced from c-oryzanol-containing by-products by hydrolysis reaction, for example, soapstock from rice bran oil processing [15,16].…”