บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

The use of sulfur dioxide and low pH treatment to control lychee (Litchi chinensis Sonn.) pericarp browning.

Underhill, S. J. R.; Gardiner, S.; Prasad, A.;

Development of postharvest handling technology for tropical tree fruits: a workshop held in Bangkok, Thailand, 16-18 July 1992. Year: 1994 Pages: 30-35 Ref: 17 ref.

1994

บทคัดย่อ

The use of sulfur dioxide and low pH treatment to control lychee (Litchi chinensis Sonn.) pericarp browning.

ABSTRACT

Browning has been attributed to the by-products of phenolic degradation by polyphenol oxidase [catechol oxidase] activity (PPO, EC 1.10.3.2). Fumigation of lychee fruits with 1.2% sulfur dioxide has previously been reported to inhibit PPO activity. This treatment also causes a rapid bleaching of the pericarp, due to the formation of a colourless anthocyanin-SO3H complex. Results of experiments with cv. Tai So (Mauritius) fruits showed that acidification of the fruits with 1N HCl resulted in an immediate improvement in pericarp colour of sulfur dioxide-treated fruits. Acidification is suggested to reverse the bleaching effect by promoting sulfur dioxide disassociation from the pigment complex. Increased pigment stability caused by acid-induced structural changes and possible Cl-ion inhibition of PPO activity may also contribute to colour improvement. Acidification did not reduce the eating quality of the aril. Total titratable acid and pH levels were consistent with little penetration of HCl into

 the aril. Pericarp colour recovery was very stable, with no deterioration observed after 12 weeks' storage at 23 deg C and 60% RH.