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Canned peaches acidified with clarified lemon juice were prepared to find a more natural product that fits the new market for ecological products, and also new alternatives for using lemons. The effects of lemon juice on color, juiciness and acidity-sweetness ratio were studied.

A study examines the aroma of canned peaches, which are treated with turbid and clarified lemon juice. Distillation process and spectrometry is used in the study.

Byline: M. Moliner (1), L. Coll (1), J. M. Ros (1), J. Laencina (1) Keywords: Key wordsaPectin; Pectic enzymes; Cross-flow filtration; Mandarin segment membrane Abstract: aThis study is concerned with the cross-flow filtration of pectic substances, produced by the enzymatic treatment of membranes of mandarin segments, using several filtration membranes with pore sizes of between 0.45 um and 30 kDa. Pectic substances solubilised in the digestion medium were polymers with an average molecular weight of 90--100 kDa. Pectin was retained by the membrane with a 100-kDa pore size. As a result of the addition of enzymes, pectin was degraded to a mixture of galacturonic acid and galacturonic acid oligomers, which appeared to be distributed between the retentate and the permeate. The final filtration rate of galacturonic acid oligomers was close to 100% when enzymes were present at the filtration membranes. In the absence of enzymes, the filtration rate ranged from 5% to 15%, and the permeation flux tended to decrease. The enzymatic treatment had an important effect on the resistances of the filtration membranes, and also caused a decrease in viscosity. These two factors were responsible for the increase in the permeate flux after the addition of enzymes, where this flux was almost as high as when filtration commenced. Author Affiliation: (1) CEBAS-Consejo Superior de Investigaciones Cientificas &amp Departamento de Tecnologia de los Alimentos, Universidad de Murcia, Campus de Espinardo, E-30100 Murcia, Spain, ES Article note: Received: 27 October 1997

Byline: M. D. Coll (1), L. Coll (2), J. Laencina (3), F. A. Tomas-Barberan (1) Keywords: Key wordsaLemon; Citrus limon; Flavanones; Eriocitrin; Hesperidin Abstract: aThe flavonoids present in the wastes and residues obtained during the industrial processing of lemons were characterized and quantified. Selected products of the juice-extraction line and essential-oil-recovery line were studied. Industrial lemon juice is characterized by containing hesperidin and eriocitrin as the main flavonoid glycosides (130 ug/ml), other minor flavanones and C-glycosylflavones. After the concentration process, the concentrated juice contained a 5-fold increase in the concentration of flavonoids, but some of the hesperidin present in the initial juice was lost. The flavanone glycosides were mainly concentrated in the peel and solid residues, where hesperidin was present as the prevailing flavonoid with concentrations of up to three times higher than those of eriocitrin. In liquid residues eriocitrin was the main flavonoid. The solid residues (peel and frit precipitates) were the most interesting sources for the industrial recovery of flavonoids (13 kg/t processed lemons). Author Affiliation: (1) Laboratorio de Fitoquimica, Departamento de Ciencia y Tecnologia de Alimentos, CEBAS (CSIC), P.O. Box 4195, E-30080 Murcia, Spain e-mail: fatomas@natura.cebas.csic.es, ES (2) Laboratorios Ecosur, S.A.L. C/Barriomar 34, E-30010 Murcia, Spain, ES (3) Departamento de Tecnologia de Alimentos, Facultad de Veterinaria, Universidad de Murcia, Campus Espinardo, E-30100 Espinardo (Murcia), Spain, ES Article note: Received: 8 October 1997

Studies of red, rose and carbonic wines from Monastrell grapes subjected to yeast fermentation reveal that rose vinification produces higher ester and acid concentration than red wine. This is due to lower fermentation temperature and shorter skin contact time. Carbonic maceration produces wine that is closer to rose than red wine in the composition of aromatic compounds.