Applications of aged powders of spray-dried whey protein isolate and ascorbic acid in the field of food safety

Abstract

Whey protein isolate (WPI)-ascorbic acid (AA) solutions were used to generate powders using spray drying technology. The powders changed color during storage. In this study, spray-dried powders with different ratios of WPI to AA were aged under different conditions. Significant redness generation was observed by heating spray-dried WPI-ascorbic acid powders up to 80 °C rapidly, and redness was generated over a longer time (up to 3 to 5 days) at room temperature. This change in redness was used to develop a packaging indicator for tracking temperature and time, which may be used to indicate the degree of food freshness by visual observation. Another application was to make the aged powders into tablets, and red liquid extracts have been leached out of the tablets into aqueous solutions. The colors of the solutions with the aged WPI-AA powders and their red extract changed at different pHs (from 3 to 11). These extracts were coated onto paper to create low toxicity pH indicators for food testing.

Keywords:

• Spray drying
• color change
• time-temperature tracking
• pH indicator

Author contribution statement

Chao Zhong: Conceptualization, Methodology, Formal analysis, Investigation, Writing - original draft; Songwen Tan: Conceptualization, Methodology, Investigation; Zelin Zhou: Investigation, Methodology; Xia Zhong: Investigation; Timothy Langrish: Resources, Writing - review & editing, Supervision.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that supports the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This research is supported by the Centre for Advanced Food Engineering (CAFE) at University of Sydney.