Effects of deodorization on the physicochemical index and volatile compounds of purple sweet potato anthocyanins (PSPAs)

• Purple sweet potato anthocyanins (PSPAs) crude extract were deodorized.
• Deodorization was conducted by AB-8 resin purification and chitosan adsorption.
• Impurities of sugars and proteins in PSPAs had been effectively removed.
• Volatile substances in PSPAs were changed and unpleasant odors were decreased.

To produce high quality purple sweet potato anthocaynins (PSPAs) extract, a deodorization process was developed and its effects on the physicochemical index including total anthocyanins, total sugar and protein, soluble solids, color values, degradation index (DI), brown index (BI) and clarity were investigated. The product sensory quality was also evaluated. The volatile compounds were analysed by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC/MS). The results indicated that using AB-8 macroporous resin purification coupled with chitosan adsorption could be an effective method in deodorization of the anthocyanin crude extract from purple sweet potato. Some byproducts in the anthocyanin crude extracts, such as sugars and proteins, had been removed by about 85% and 76% respectively. Compared with the raw anthocyanin extract, the volatile substances in the final product of PSPAs were changed and the unpleasant characteristic odors, such as some alcohols, aldehydes, organic acids and alkanes, were decreased. However, the product yield was also decreased by about 26% after the deodorization process.