Simon Matthews
The Control of Enzymatic Browning in Fresh-Cut Produce
Mantrose Haeuser Inc
Industrial
PharmaceuticalConfectionery
Cosmetics
Agriculture
Semperfresh® - Pre Harvest Treatment on cherries to prevent rain-induced skin
cracking
Semperfresh® - Post Harvest Treatments for fruit to delay ripening
in transit and storage
Coatings to extend shelf life and maintain quality in fresh cut and
minimally processed fresh produce.
E.g. Natureseal® - Vitamins and mineral mixtures; cellulosics
Physical Responses
• Mechanical shock to tissue (bruises, cracks, fractures)
• Loss of structural integrity• Entry for contamination• Accelerates water loss• Substrate for microbes• Alter (reduce or enhance) gas diffusion• Surface debris changes appearance• White blush formation
• Elevated ethylene production• Wound response• Membrane depolarization • Elevated respiration • Oxidative reactions• Induction of enzymes• Altered phenolic metabolism / wound healing• Compositional changes
� Reduced carbohydrates, organic acids & ascorbic acid
� Toughening, softening� Loss of flavor, aroma
Physiological Responses
Simplified schematic enzymatic (polyphenol oxidase) browning
Browning
Factors Influencing Browning
• Type of product & variety• Growing conditions• Maturity of crop (picking date)• Storage conditions• Concentration of oxygen • Processing method
Sulphiting Agents
• Sulphur Dioxide• Sodium Metabisulphite• Sodium Sulphite• Sodium Bisulphite• Potassium Bisulphate• Potassium Metabisulphate
Non-Sulphite Anti-Browning Agents
• Antioxidants (reducing agents)
– Ascorbic Acid– Ascorbyl Palmitate– Ascorbic Acid Phosphate– Glutathione– Adsorbed Tocopherol– L-Cysteine
Non-Sulphite Anti-Browning Agents
• Chelating Agents
– EDTA– Sorbic Acid– Sodium Pyrophosphate– Sodium Polyphosphate– Citric Acid
• Acidulants
– Citric Acid– Malic Acid– Tartaric Acid– Phosphoric Acid
Non-Sulphite Anti-Browning Agents
• 4-Hexylresorcinol• Aromatic Carboxylic Acids
• Sodium Chloride• Calcium Chloride• (and other anions)
• Cyclodextrins
PPO Inhibitors
• Co-developed by USDA
• Powder blends of vitamins & minerals
• Sulphite-free
• Prevent oxidative browning
• Maintain texture
• Minimise water loss
• Does not impart flavour, colour or odour
• Easy to apply by dipping or spraying
Water Loss from Bramley Apples
02468
10
0 50 100 150 200
Time Hours
Perc
enta
geLo
ssAscorbic and citricacid dip
5 % NaturesealAS1 dip
5.3 % NaturesealAS5 dip
Main Applications
• Apples• Pears• Carrots• Celery• Rhubarb• Sweet Potato• Swede / Turnip• Belgian Endive
(Chicory)
• Melon• Pineapple• Mango• Limes• Stone Fruit
Snack Apple Products UK and Europe
Sanitation• Strict food safety & cleaning
procedures • Chlorine and alternatives
–(viz. Tsunami, Catallix, Citrox, Ozone etc.)
• Must maintain cold-chain• Avoid bruising
Coring and Slicing
Removal and segregation of core tissue
Sharp corer and cutting blades
Cleaning / sanitising equipment
Rinsing and sanitising slices
Apply Natureseal as soon as possible after slicing
Dipping Natureseal
Dipping
Economical use of Natureseal
Ensures complete immersion of fruit pieces
Natureseal solution can be chilled
Simple to use and clean
Concentration Meter
Micro Filtration of Natureseal Solution
Packaging
• Ensure aerobic atmosphere throughout shelf life
• Avoid excessive build up of carbon dioxide
– Blown packs– Fermentation (Flavours)– Yeast growth– Reduce weight loss
• Increases shelf life
Packing
Summary
• Natureseal products • Patented powder blends• Effective on wide range of produce• Extends shelf life (except microbial)• With apples up to 21 days• Does not affect taste