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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Citrus and Other Subtropical Products Research » Research » Publications at this Location » Publication #335413
Research Project: Quality, Shelf-life and Health Benefits for Fresh, Fresh-cut and Processed Products for Citrus and Other Tropical/Subtropical-grown Fruits and Vegetables

Location: Citrus and Other Subtropical Products Research

Title: Formulating a natural colorant containing wax for a one-step color-add application for fresh citrus

Author
item SUN, XIUXIU - University Of Florida
item Baldwin, Elizabeth - Liz
item RITENOUR, MARK - University Of Florida
item HAGENMAIER, ROBERT - Retired ARS Employee
item Bai, Jinhe

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2016
Publication Date: 4/1/2017
Citation: Sun, X., Baldwin, E.A., Ritenour, M., Hagenmaier, R., Bai, J. 2017. Formulating a natural colorant containing wax for a one-step color-add application for fresh citrus. HortScience. 52(3):408-412.

Interpretive Summary: Previously we found that paprika and annatto extracts are comparable to Citrus Red Number 2 (CR2), a group 2B carcinogen listed by European Union (EU) and International Agency for Research on Cancer (IARC), as natural colorant alternatives. In this research, our goal was to formulate a ‘natural colorant containing carnauba wax’ which can be applied in a one-step application and has appearance and quality enhancing effects comparable to currently used commercial two-step ‘dye then wax’ applications. The results showed that a one-step application of paprika-containing carnauba wax was comparable to two-step of ‘CR2 then wax’ applications in improving fruit appearance and extending storage life.

Technical Abstract: In Florida, early season citrus fruits usually reach full maturity in terms of internal quality while their peel often does not turn orange in color after degreening due to insufficient buildup of carotenoids. For huanglongbing-affected orange trees, the fruit may never turn orange the entire harvest season, despite experiencing cold weather. Improvement of early season citrus peel color is important to the citrus industry to better meet consumer expectations. Occasionally, packinghouses apply a dye, Citrus Red Number 2 (CR2), to improve the surface color of oranges, temples, and tangelos prior to applying a fruit wax to impart shine, retain moisture, and slow fruit senescence. In a previous report, we determined that paprika and annatto, natural plant extracts, are comparable to CR2 as natural colorant alternatives. In this research, the goal was to formulate a natural colorant (annatto, paprika, or paprika oleoresin) containing carnauba wax coating. The coatings were first evaluated for color, shine, moisture retention and internal gas content. Control fruit were coated with carnauba wax alone, or dyed with CR2 then coated with carnauba wax. The effects were assessed under different temperature and light exposure conditions to simulate commercial storage and marketing. The results showed that a one-step application of paprika-containing carnauba wax was comparable to the two-step (‘CR2 then wax’) applications in improving fruit appearance and modification of internal gas composition.