Application of Saponin for Cholesterol Removal from Pacific White Shrimp (Litopenaeus vannamei) Lipid

Abstract

The removal of cholesterol from lipid obtained from Pacific white shrimp (Litopenaeus vannamei) cephalothorax using saponin in conjunction with celite under various conditions is investigated. Various lipid:saponin ratios (1:2, 1:4, and 1:6, W/W) with different lipid:solvent ratios (1:20, 1:40, and 1:80, W/V) are employed with a treatment time of 4 h. The highest cholesterol removal (88.77 ± 0.18%) is obtained with a lipid:saponin ratio of 1:6 and 20 volumes of 50% ethanol. As the treatment time is increased from 1 to 4 h, higher cholesterol removal is achieved. Lipid peroxides and conjugated dienes are higher in the lipid after cholesterol removal compared to untreated lipid, while thiobarbituric acid reactive substances, the ρ‐anisidine value and free fatty acids are reduced. However, the polyunsaturated fatty acid (PUFA) content in the saponin‐treated lipid (18.06 ± 0.37 g/100 g−1) is higher than that of untreated lipid (15.80 ± 0.17 g/100 g−1). FTIR spectra confirmed the formation of hydroperoxides, with lower aldehyde, phospholipid and free fatty acid contents in the cholesterol‐removed lipid. The process developed employing saponin is able to produce crude shrimp lipid with a pronounced decrease in cholesterol, but augmented PUFAs, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).Practical Applications: Shrimp lipid is a vital byproduct capable of extraction from cephalothorax. Due to the presence of astaxanthin, EPA and DHA, shrimp lipid is considered to be a highly useful nutraceutical product. However, the cholesterol content of shrimp lipid is a major constraint on its human consumption. The negative impact of cholesterol content can be overcome by lowering the cholesterol content. Saponin treatment of shrimp lipid is able to reduce the cholesterol level and increase the PUFA, thus solving the high cholesterol problem and also gaining augmented health benefits.

Comparative Study of Astaxanthin, Cholesterol, Fatty Acid Profiles, and Quality Indices Between Shrimp Oil Extracted From Hepatopancreas and Cephalothorax

“…The peak height of aldehydes was greater in HPO, compared to that of CPO, reflecting the augmented formation of secondary lipid oxidation products in HPO. Phosphate attached with the carbonyl group indicates the presence of higher phospholipids in CPO ( 6 ). However, the peak was lowered in HPO, indicating the lower phospholipid content.…”

“…The ethanol-soluble polar and neutral lipids such as cholesterol, astaxanthin, fat-soluble vitamins, phospholipids, and other carotenoids were separated from insoluble non-polar lipids. The non-polar lipids mainly triglycerides were crystallized due to the insolubility in ethanol ( 6 ). In the current study, preliminary identification of lipid components in the ethanolic fraction was done by liquid chromatography-mass spectrometry (LC-MS) ( Table 2 ).…”

“…Shrimp oil was extracted using the hexane/isopropanol extraction method as detailed by Raju and Benjakul ( 6 ). First, cephalothorax and hepatopancreas were blended with a blender at high speed for 1 min to obtain a homogenous paste.…”

“…The cholesterol and astaxanthin contents were quantified by high-performance liquid chromatography (HPLC) (Waters 2695 series, Milford, MA, USA) ( 6 , 19 ) equipped with a reverse-phase Thermo scientific BDS-C18 column (5 μm; 150 × 4 mm) following the method of Raju et al ( 20 ). Each oil sample (100 μl) was dissolved in 1 ml of ethanol.…”

“…In addition, the residues after oil extraction have become less when hepatopancreas is used, compared to the cephalothorax. Shrimp oil is rich in astaxanthin, astaxanthin esters, and polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ( 6 , 7 ). These bioactive compounds are highly beneficial for improving human health.…”