Microwave-assisted extraction of phenolic compounds from grape seed.
A microwave-assisted extraction technique was developed to optimize the extraction of phenolic compounds from grape seeds. The microwave power (300-150W) and time of extraction (20-200s) were varied during the optimization process. The polyphenol content of the resulting extracts were measured as mg of tannic acid equivalent per gram of crude extract (mg TAE/g of crude extract), using a Folin-Ciocalteau reagent. In general, neither the time nor the power had a significant effect on the overall % yield (average of 13.5%) and on the polyphenol content (392 mg TAE/g of crude extract) of the extracts. However, when the solvent polarity was changed by the addition of 10% water, the yield increased to 15.2% and the polyphenol content increased to 429 mg TAE/g of crude extract.
Hong
N
N
Chinese Research Academy of Environmental Sciences, Anwai, Beijing.
Yaylayan
V A
VA
Raghavan
G S
GS
Paré
J R
JR
Bélanger
J M
JM
D000975:Antioxidants / Q000032:analysis / Q000302:isolation & purification*; D005223:Fats / Q000032:analysis / Q000302:isolation & purification; D005419:Flavonoids; D005638:Fruit / Q000737:chemistry / Q000528:radiation effects; D047348:Hydrolyzable Tannins / Q000032:analysis; D000432:Methanol; D008872:Microwaves; D010636:Phenols / Q000032:analysis* / Q000302:isolation & purification*; D010936:Plant Extracts / Q000737:chemistry; D011108:Polymers / Q000032:analysis* / Q000302:isolation & purification*; D059808:Polyphenols; D012639:Seeds / Q000737:chemistry* / Q000528:radiation effects; D013997:Time Factors; D027843:Vitis / Q000737:chemistry* / Q000528:radiation effects; D014867:Water / Q000032:analysis
D000975:Antioxidants; D005223:Fats; D005419:Flavonoids; D047348:Hydrolyzable Tannins; D010636:Phenols; D010936:Plant Extracts; D011108:Polymers; D059808:Polyphenols; D014867:Water; D000432:Methanol