Detection of Cyanidin in Different-colored Peanut Testae and Identification of Peanut Cyanidin 3-sambubioside

Abstract

Peanut testae are potent sources of polyphenols. When the water extracts and acid hydrolysates of five different-colored testae were analyzed by HPLC, chromatograms monitored at 280 nm varied remarkably, whereas two major peaks in the chromatograms monitored at 530 nm were detected only in kernels having completely or partially black color. After acid hydrolysis of the extracts, cyanidin was detected in each of the hydrolysates. By respectively subjecting the black testae of raw and roasted (175 degrees C for 20 min) kernels of a black colored cultivar to water extraction and HPLC analysis, a prominent peak was detected in both extracts. The structure of the substance under those peaks was identified by mass and NMR spectrometry as cyanidin 3-sambubioside in peanut testae for the first time. Subjection of cyanidin 3-sambubioside to antioxidation and anti-inflammation assessments revealed that it was a potent antioxidant and inhibitor of nitric oxide production.

Antioxidant and Anti-Inflammatory Effects of Peanut Skin Extracts

“…The observed suppression of PGE 2 formation in this study maybe a consequence of the high levels of procyandins present in the extracts. A study using acid hydrolyzed aqueous extracts from peanut skins reported inhibition of PGE 2 activity [41]. The authors attributed this activity to the presence of cyandin 3-sambubioside, which is an anthocyanidin originating in peanut skins.…”

Effects of the Roasting Process Over the Content of Secondary Metabolites from Peanut Grains (Arachis hypogaea. L) with Different Colorations of Testa

“…() and Cheng et al . (), high levels of flavonoids are found in the testa of the peanut grain, and heating was found to cause an increase from 21.30 to 25.5 mg EC/g via processing, with minor changes observed in the content of flavonoids when the grains were subjected to thermal processing under mild conditions. During processing, no major changes were found in the content of IF (data not shown) because the majority of flavonoids are in a soluble form or coupled with simple or multiples sugars, which are quantified in the soluble fraction (Acosta‐Estrada et al .…”

Antioxidant Activity of Anthocyanins in Common Legume Grains

“…Some people believe that peanuts with black testa are good for their health. Cheng et al (2009) also reported that raw and roasted black king kong had the anthocyanin content in their testa. The research identified cyanidin-3-sambubiose as the major anthocyanin in black peanut testa.…”

“…The testa color of peanut varies widely, which are white, tan, red, purple, and wine. In Taiwan, peanuts with different kernel colors are consumed, and a black-seeded cultivar, locally named Black King kong, is widely grown and popularly consumed (Cheng et al, 2009). Some people believe that peanuts with black testa are good for their health.…”

“…The result showed that it has a high radical-scavenging activity when tested with DPPH method. The anti-inflammatory activity was also determined, and the result indicated that the extract expressed a potent natural inhibitor of NO biosynthesis (Cheng et al, 2009). …”