Alpha-amylase inhibitory activity of collagen hydrolysate from Asian bullfrog skin and its application in dark chocolate

Abstract

The present study aimed to investigate the in-vitro antidiabetic activity of collagen hydrolysate (CH) from Asian bullfrog skin and its application as a bioactive compound in dark chocolate bars. Papain (3% [w/w]) was used to obtain CH with a simultaneous conjunction of ultrasound. CH possessed α-amylase inhibitory activity with an IC₅₀ value of 3.60 mg/mL, while results from inhibition reaction kinetics revealed that CH inhibited α-amylase in a non-competitive mode. Different concentrations (0.5, 1.0, and 2.0% [w/w]) of CH were then fortified into dark chocolate bars, and the physicochemical characteristics, breaking strength, and rheological behaviour of the resulting chocolate were investigated and compared with a control (without CH addition). A higher level of CH significantly enhanced antidiabetic activity against α-amylase (p ≤ 0.05) in chocolate bar. Chocolate bar with 2% CH complied with the nutritional claim requirement for ‘source of protein’ with lower fat content and energy value, while sensory evaluation revealed good organoleptic properties.

Graphical Abstract

Keywords:

• Antidiabetic
• bioactive peptides
• functional food
• rheology
• thermal behaviour
• texture

REVIEWING EDITOR:

• M. Luisa Escudero-Gilete, Universidad de Sevilla, Spain

SUBJECTS:

• Nutrition; Food Additives & Ingredients; Food Chemistry

Authors’ contributions

S.I.: conceptualization, methodology, software, data curation, writing –original draft preparation, visualization, investigation, writing – review & editing. S.B.: writing – review & editing. A.B.S.: writing – review & editing. S.K.: conceptualization, methodology, writing – original draft preparation, visualization, investigation, writing – review & editing. S.N.: writing – review & editing.

Disclosure statement

The authors declare no conflict of interest.

Ethical approval

All experiments this study were performed with the approval of the Research Ethics Committees of King Mongkut’s Institute of Technology Ladkrabang (EC-KMITL_64_039).

Additional information

Funding

This work was supported by King Mongkut’s Institute of Technology Ladkrabang Research Fund under KMITL Doctoral Scholarship [KDS2020/032], Chiang Mai University was also acknowledged.