Quantitative analysis of pigments in the refining process of edible vegetable oils and fats
Quantitative analysis of pigments in the refining process of edible vegetable oils and fats
Vegetable oils and fats can be extracted from oilseeds by leaching or pressing, and vegetable crude oils are rich in natural pigments, especially fat-soluble pigments such as chlorophyll, lutein, zeaxanthin and β-carotene are the most common. Among them, lutein and zeaxanthin are tautomers, which can scavenge free radicals, have strong antioxidant properties, reduce the risk of chronic diseases and cancer, prevent and treat diabetes, reduce the damage of blue light on vision and prevent and slow down age-related macular degeneration, etc. β-carotene is the precursor of vitamin A, which is the main source of vitamin A. It has strong antioxidant effects and can increase the immune function of the human body. It has a strong antioxidant effect and can increase the immune function of human body, and has good anti-cancer effect. However, too dark color will affect the appearance quality of fats and oils, and it is difficult to meet the consumer habits, and most natural pigments are unstable to heat and difficult to be preserved in the refining process.
Analysis of pigment content in different crude oils
The pigment composition in different kinds of vegetable oils and fats varies. The content of lutein and β-carotene in soybean crude oil is relatively high, ranging from 2.85 to 6.71 mg/kg and 2.45 to 10.50 mg/kg, respectively; the content of β-carotene and chlorophyll in rapeseed crude oil is relatively high, ranging from 12.30 to 49.90 mg/kg and 4.87 to 26.30 mg/kg, respectively; the content of zeaxanthin and β-carotene in corn crude oil is relatively high. The content of corn crude oil was relatively high in the range of 12.40~15.80 mg/kg and 4.75~5.55 mg/kg, respectively; the total amount of four natural pigments in soybean crude oil, canola crude oil and corn crude oil were 7.28~24.38 mg/kg, 23.13~95.80 mg/kg for soybean crude oil, 23.13~95.80 mg/kg for canola crude oil and 17.93~23.73 mg/kg for corn crude oil, respectively. The total amount of pigments in rapeseed crude oil was significantly greater than that in soybean crude oil and corn crude oil.
Trend analysis of pigment content of different vegetable oils and fats in each section
The pigment removal rates of vegetable oils and fats in the neutralization section ranged from 5.6% to 38.3% for lutein, 1.4% to 35.1% for zeaxanthin, 0.0% to 19.1% for β-carotene, and 4.4% to 41.9% for chlorophyll in soybean oil, and 26.0% to 92.9% for lutein, 1.9% to 43.8% for zeaxanthin, 2.4% to 20.2% for β-carotene, and 9.3% for chlorophyll in rapeseed oil. 20.2%, chlorophyll 9.2%-22.2%, lutein 19.5%-42.3%, zeaxanthin 34.6%-43.5%, β-carotene 5.2%-6.8%, chlorophyll 76.9%-93.7% in corn oil; the total pigment removal rates of vegetable oils and fats in the decolorization section were 90.5%-100% for lutein, 100% for zeaxanthin, and 59.5% for β-carotene in soybean oil. 100%, β-carotene 59.3%~100%, chlorophyll 83.5%~98.7% in soybean oil, 96.9%~100%, 100%, β-carotene 24.8%~100%, chlorophyll 97.2%~99.7% in rapeseed oil, 100%, 100%, β-carotene 100%, chlorophyll 87.5%~98.7% in corn oil. Chlorophyll 87.5%～98.9%; in deodorized oil, except for chlorophyll, all other pigments were below the detection limit, and the total removal rate of chlorophyll in deodorized section was 85.7%～98.7% for soybean oil, 97.9%～99.9% for rapeseed oil, and 92.3%～98.9% for corn oil. All four natural pigments in soybean oil decayed most significantly in the decolorization section; lutein in canola oil decayed most significantly in the neutralization section, and the other three pigments decayed most significantly in the decolorization section; chlorophyll in corn oil decayed most significantly in the neutralization section, and the other three pigments decayed most significantly in the decolorization section.
The pigment composition and content of the three vegetable oils and fats were different, but there was a certain pattern in their content range and composition: canola oil was relatively rich in pigments, followed by corn oil and soybean oil; the top two pigment ratios in crude oil were soybean oil The top two pigments in crude oil are β-carotene and lutein in soybean crude oil, β-carotene and chlorophyll in canola crude oil, and zeaxanthin and β-carotene in corn crude oil. The difference in pigment content of different vegetable oils and fats can explain the color difference to some extent.
The pigment decay trends of the three vegetable oil refining sections were as follows: the four natural pigments in soybean oil decayed most significantly in the decolorization section; lutein in rapeseed oil decayed most significantly in the neutralization section, while the other three pigments decayed most significantly in the decolorization section; chlorophyll in corn oil decayed most significantly in the neutralization section, while the other three pigments decayed most significantly in the decolorization section.
By quantitatively analyzing the content of four natural pigments in three vegetable oils and fats in the refining section and exploring their change patterns, it provides a reliable way to evaluate the precise processing and moderate processing of vegetable oils and fats.
