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ACTION PLAN. Control of diseases and physiological disorder in fresh-cut pineapple using phenyllactic acid bio-compound Implemented by Bui Kim Thuy & Nguyen Thi Lan Huong Vietnam Institute of Agricultural Engineering & Postharvest Technology Presented by Nguyen Thi Lan Huong
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ACTION PLAN Control of diseases and physiological disorder in fresh-cut pineappleusing phenyllactic acid bio-compound Implemented by Bui Kim Thuy & Nguyen Thi Lan Huong Vietnam Institute of Agricultural Engineering & Postharvest Technology Presented by Nguyen Thi Lan Huong Mekong Institute, Thailand, Nov.1, 2011
INTRODUCTION • Great potential for production of fruits and vegetables in Vietnam • - The climate and soil: suitable for culturing tropical FAV • In 1999: the government approved national project of developing vegetables, fruits, flowers and bonsai in period of 1999-2010. • 2003: area reached 1.27 mil. hectares with • yield of 13.8 million tons. • In which, vegetables: 577,000 ha, • yield: 8.18 million tons • → Annual average increase of over 13% in area and 2% in yield.
Consumption demand • - Domestic consumption of fruit: ≈ 3.5 million/year, • 50 kg/head/year in urban and • 20-30 kg/head/year in rural areas • Increase of using canned, dried fruits and vegetables • Increase of demand for convenient products that • preserve their nutritional value, • retain a natural color, flavor and texture, and contain fewer additives • (Jongen, 2002) • → Fruit industry needs to diversify types of minimally processed fruits
Fresh-cut fruits Consumption with double digit growth + Demand for diversified forms of fruits + Most fruit is consumed at home = Great opportunity for FRESH-CUT FRUIT
Fresh-cut fruits (cont.) • - Highly perishable products due to their intrinsic characteristics and minimal processing • Microbial growth, • Sensorial attributes decays, and • Loss of nutrients • (Ayala Zavala et al., 2008a). • - These drawbacks are caused by the steps in the minimal processing like peeling and cutting which promote an increment in the metabolic rate, enzymatic reactions, and release juice (Rapisada et al., 2006). • - Chemical synthetic additives reduce decay rate, but chemical residues could affect health and environmental pollution, • → Need to develop alternative methods for controlling fresh cut fruit decay
Phenyllactic acid (PLA) C6H5CH2CHOH==COOH • A novel antimicrobial compound with broad inhibitory activity, higher stability and safety Gram(+) and gram(-) bacteria. Mold, fungi (mycotoxigenic species) Dieuleveus et al., 1998a, 1998b • Anti-oxidant property • Practical application as a novel bio-preservative in the food industry. • Intl. research on PLA: quite new (since 1998) • PLA was no toxicity on animals and human health • (Oberdoester et al., 2000)
RESULTS I: PATHOGEN INHIBITION • Inhibition activity of PLA against some pathogens in vitro • Antifungal activity of PLA against three fungal pathogens
Antifungal activity of PLA against three fungal strains (cont.) The inhibitory ability of PLA against 3 fungal strains PLA 20 mg/ml inhibitable 50.1% of P.digitatum population, but 28.3 and 20.1% of A.niger and A.flavus, PLA 50 mg/ml:
Antibacteria activity - Vibriocholerae was the most sensitive, E.coli was the least sensitive - These findings would be illustrated more clearly by calculating percentage inhibition of tested population
Antibacteria activity (cont’.) → PLA 25 mg/ml absolutely inhibited against V.cholerea and S.typhi (100% of population) while PLA at this level could inhibit 95.6% of E.coli population
Inhibition activity of PLA against some pathogens infresh-cut pineaple • Total aerobic bacteria → Total aerobic bacteria at PLA 20 mg/ml and 25 mg/ml was the lowest and lasted shelf-life of pineapple till 12 day storage.
RESULT II: PHYSIOLOGICAL CHANGES • Color changes of fresh cut pineapple - ∆E value was the highest in the control (increased from 0.0 up to 11.27 after 6 days), the lowest in the test treated by PLA 20 mg/ml (∆E was only 6.48 after 12 day storage) → fresh-cut pineapple treated with PLA could have the shelf-life longer than non-treated one.
CONCLUSIONS • - In vitro study showed that PLA had a board antimicrobial spectrum: controlled some harmful fungi, and pathogenic bacteria • 40-50 mg/ml can absolutely inhibit 100% population of A.niger, A.flavus, and P.digitatum • 25-30 mg/ml can absolutlely inhibit 100% of population of E.coli, S.typhi, and V.cholerea • In vivo study showed that PLA acts as a bio-preservative in fresh-cut pineapple in minimal processing when it kept the quality of fresh-cut pineapple for 12 days in cool temperature • → PLA acts as a prospective bio-preservative compound applicable in food industry • → More experiments are being conducted to surely conclude about the applicability of PLA