The influence of enzymatic treatment of mash on the analytical composition of apple juice

Abstract

Five apple juices were produced on a pilot scale by crushing the fruit, treating the mash with pectolytic enzymes, pressing, extracting water from the pomace, pasteurization, treatment of the juice with enzymes, combined gelatin/silica sol fining and final ultrafiltration. The temperature of the mash treatment was either ambient or one of 30, 40, 50 or 60°C, in order to test whether this led to different compositional changes in the corresponding juices. The main emphasis was put on detection of D-galacturonic acid as the indicator substance for the extent of the enzymatic treatment. In the pasteurized raw juices after pressing we found values from 226 to 398 mg L )1 . A distinct increase of the galacturonic acid levels could be observed during the clarification steps. Enzymatic juice treatment raised the concentrations to 580-720 mg L )1 . After ultrafiltration, final values of 790-1100 mg L )1 were measured. Generally, the highest values were found in the 50°C sample, which is the optimum temperature for pectinase activity. This was also true for the colloid concentrations and polyphenols. The influence of the temperature of the enzymatic mash treatment on other characteristic juice parameters like total titratable acidity, density, sugar, and minerals concentrations was low.

Phenolic profile and antioxidant activity in apple juice and pomace: effects of different storage conditions

“…During apple tissue disintegration the enzyme is released from cell walls and can catalyse the oxidation of phenolic compounds to corresponding o-quinones which easily condense to brown pigments. According to the data of van der Sluis et al [12], some juices maintained only 3-10% of the antioxidant activity of the fresh fruit [17], as the antioxidant activity of juices is positively correlated with the content of phenolics [18,19].…”

Optimization of Enzymatic Clarification of Green Asparagus Juice Using Response Surface Methodology

“…Moreover, raw asparagus juice is unstable and tends to settle during preservation due to the sedimentation of some suspended solids such as polysaccharides (pectin, cellulose, hemicellulose, and lignin), proteins, and polyphenols (Vaillant and others 2001). Therefore, enzymatic treatment is necessary to increase juice yield and stability (Will and others 2002). …”

Modulating polyphenolic composition and organoleptic properties of apple juices by manipulating the pressing conditions

“…The second most abundant polyphenols in apple are phenolic acids, namely chlorogenic acid then p-coumaroylquinic acid. These are usually the main polyphenols in the juices and ciders (Alonso-Salces et al, 2004;Mihalev, Schieber, Mollov, & Carle, 2004;Oszmianski & Wojdylo, 2007;van Buren, de Vos, & Pilnik, 1973;van Buren, de Vos, & Pilnik, 1976;van der Sluis et al, 2002;Will, Schulz, Ludwig, Otto, & Dietrich, 2002), though chlorogenic acid is the primary substrate of apple polyphenol oxidase (Goodenough & Lea, 1979;Janovitz-Klapp, Richard, Goupy, & Nicolas, 1990;Le Bourvellec, Le Quéré, Sanoner, Drilleau, & Guyot, 2004b). The third class is that of monomeric flavan-3-ols, both (À)-epicatechin and a minor amount of (+)-catechin.…”