Abstract:

The fruit quality and juice-making suitability of there different guava (Psidium guajava L．) cultivars were evaluated, and their sugar and acid compositions and antioxidant activities were analyzed. The results showed that“Zhenzhu”has the highest content of total soluble solids (TSS) (9.11%) and its titratable acids is also high (0.36 g/100 ml); “Xinshiji” has the highest contents of VC (4.96 g/L), total phenolics (2.13 g/L) and TAC (67.26 mmol/L). A comprehensive evaluation showed that “Xinshiji” scores the highest in fruit quality, while “Zhenzhu” scores the highest in juice-making suitability. Fructose, glucose and sucrose are the predominant sugars in guava. The three guava cultivars are all monosaccharide-prevalent, with higher fructose content. Different cultivars contain different acid compositions. The main acids in“ Xinshiji” are citric acid, succinic acid and propionic acid, while those in“ Zhenzhu” and“ Shuijing” are citric acid, succinic acid, α-ketoglutaric acid, propionic acid, tartaric acid and pyruvic acid. Among them, citric acid and succinic acid are the two dominant organic acids“. Xinshiji” is the highest in antioxidant activity.

Key words: guava, fruit quality, sugar composition, acid composition, antioxidant activity