Browning and pinking or bitterness reduction using PVPP

Purpose

Calculate the amount of PVPP to add in order to remove color defects and or reduce bitterness.

Background

PVPP is a synthetic, high-molecular-weight clarifying agent made up of cross-linked monomer of polyvinylpyrrolidone. PVPP has long been used in the beverage industry as a polyphenol adsorbent (Siebert and Lynn, 1997, 1998). Although, it has been called as a “protein-like” fining agent, insoluble PVPP interacts with only few reactive groups. Hence, PVPP is used for binding and removing smaller phenolic compounds such as catechins and anthocyanins, which are responsible for causing browning and bitterness in wines. However, PVPP, along with charcoal and casein, can remove resveratrol, a component that imparts certain health benefits (Castellari et al., 1998). Typical usage level of PVPP for wines ranges from 1 to 6 lb (1000 gallons)−1 (or 0.12–0.72 g L−1) (Morris and Main, 1995).
PVPP has also been recently tested in wines to eliminate odours described as mushrooms, mouldy, camphoric or earthy due to the presence of geosmin and ochratoxin A (OA). As it is also a very fine powder, adding bentonite will compact the sediment.

REFERENCES:

• Encyclopedia of Food Chemistry, (2019), Harsh P. Sharma, Aditya, Madan and D.C. Joshi;
• Managing Wine Quality: Oenology and Wine Quality (2010) - R. Marchal, E.J. Waters;