By John Considine and Elizabeth Frankish (Auth.)

ISBN-10: 0124080812

ISBN-13: 9780124080812

Show description

Read Online or Download A Complete Guide to Quality in Small-Scale Wine Making PDF

Best botany books

E. E. Conn's Secondary Plant Products. A Comprehensive Treatise PDF

The Biochemistry of vegetation: A finished Treatise, quantity 7: Secondary Plant items makes a speciality of the biochemistry of secondary compounds, together with tissue tradition and differentiation, complexes, and plant systematics. the choice first elaborates at the physiological roles of secondary usual items, tissue tradition and the examine of secondary average items, and turnover and degradation of secondary normal items.

Read e-book online Evolution by natural selection : confidence, evidence and PDF

A continual argument between evolutionary biologists and philosophers revolves round the nature of typical choice. Evolution by means of common choice: self assurance, facts and the distance explores this argument through the use of a conception of endurance as an intentional foil to ascertain ways that related theories could be misunderstood.

Extra resources for A Complete Guide to Quality in Small-Scale Wine Making

Sample text

Yellowing, then browning is not a simple chemical reaction. It requires the presence of an enzyme and/or a metal ion and oxygen and a substrate. In white and also in red wines, the phenols, caftaric and coutaric acids, are the primary substrates (Singleton, 1985). In grape juice, must, glutathione intervenes: PPO Caftaric acid 1 O2 ÀÀÀÀÀÀÀÀÀ! 1 Glutathione Caftaric quinone ÀÀÀÀÀÀÀÀÀ! S-Glutathionyl caftaric acid This product does not brown, leading Singleton (1985) to conclude that grape musts possess a built-in system to protect against browning, at least to a degree.

All terpenes share a common metabolic origin, although some are formed de novo while others are a product of senescence. Terpenes are common in nearly all aromatic plant products, otherwise known as essential oils. ). 19). As such, they are not volatile nor can the enzymes in saliva (α-amylase) or many yeasts (zero or very low levels of β-glycosidase) release the free, volatile, aroma compound. The natural hydrolases present within the grape have a low activity at wine pH, are inhibited by sugars in the juice and are not active with all sugar glycosides found naturally (reviewed by Maicas and Mateo, 2005).

Data from Francis and Newton, 2005). known series, and only through application of relatively recent advances in mass spectrometry and stable isotopebased techniques has the importance of this group been unveiled. 23). Descriptors for this group vary from the exquisite to the disgusting, presumably depending on concentration and matrix (Francis and Newton, 2005). Many of the unpleasant-smelling sulfur compounds originate from the degradation of the sulfur-containing amino acids, cysteine and cystine, which are important protein-forming amino acids.

Download PDF sample

A Complete Guide to Quality in Small-Scale Wine Making by John Considine and Elizabeth Frankish (Auth.)


by Mark
4.4

Rated 4.25 of 5 – based on 8 votes