Determination of organic acids and sugars in guava (Psidium guajava L.) cultivars by high‐performance liquid chromatography

Abstract

The major organic acids and sugars in five Florida guava cultivars were analysed by high-performance liquid chromatography. Glycolic, malic, ascorbic and citric acids were determined, citric being the major acid in all five cultivars. Ascorbic acid levels varied more than ten-fold (0.04-0.44%) among the cultivars. Trace amounts of fumaric acid were detected for the first time in guava fruit. In all cultivars, fructose was the major sugar; glucose and sucrose were also determined.

Recobrimento de goiabas com filmes proteicos e de quitosana

“…A acidez em produtos hortícolas é atribuída, principalmente, aos ácidos orgânicos que se encontram dissolvidos nos vacúolos das células, tanto na forma livre, como combinados com sais, ésteres, glicosídeos, etc. Em goiabas, o principal responsá-vel pela acidez é o ácido cítrico (Wilson et al, 1982). O aumento da acidez titulável pode ser explicado, em parte, pelo aumento no teor de ácido ascórbico, o qual também foi verificado em todos os tratamentos.…”

Exotics

“…Similar results were found by Mowlah and Itoo (1983), ascorbic acid content in the two cultivars examined increasing throughout maturation, ripening and storage, reaching over 270 mg.l00g-1 in both cultivars. Itoo et al (1980) reported that guava fruits have ten times more ascorbic acid than oranges; however, ascorbic acid levels have been shown to vary from 0.04% to 0.44% depending upon the cultivar (Wilson et al, 1982a).…”

“…Fructose is the major sugar present in the ripe fruits of both Florida (Wilson et al, 1982a) and Vietnamese type cultivars (Salmah and Mohamed, 1987). Fructose comprises 55.93% and 52.85% of the sugar in white and pink cultivars respectively (Mowlah and Itoo, 1982).…”

“…The change in ascorbic acid level shows a sigmoid curve (Salmah and Mohamed, 1987). Wilson et al (1982a) analysed the acid content of the ripe fruits of five Florida cultivars. While citric acid was the major acid in all the cultivars, glycollic, malic and ascorbic acid were also present, sometimes in substantial amounts; traces of fumaric acid were also detected.…”

Production of wine from over ripe guavafruit(PsidiumGuajava LSafada)and ber (Ziziphusmauritiana L Umrau) using Saccharomyces crevices Var. HAU 1

“…It is a good source of ascorbic acid, sugars, pectinand some minerals. Its flesh and skin colours vary from variety to variety depending on the pigment type and the amount [1]. Tropical Fruit juices have turn out to be important in recent years due to the overall increase in natural fruit juice consumptions as an alternative to the conventional caffeine-containing beverages such as coffee, tea or carbonated soft drink [2].…”