It will be empirical depending on the matrix, but the use of high-pressure treatment may help inactivate various fruit-based enzymes and minimize heating temperature/time, if any are necessary:

http://www.ncbi.nlm.nih.gov/pubmed/22136649

http://www.ncbi.nlm.nih.gov/pubmed/22809197

http://www.ncbi.nlm.nih.gov/pubmed/22644526

You can try combined treatments with milder heat treatments and ultrasounds or with ozone.

Considering your conditions ( no use of heat or or alchool) i suggeste using proteases enzymes that inactivate (hydrolyses) proteins (enzymes) - im considering laboratory conditions not industry level.

Add 1% Vitamine C or sulfur !

1. Dipping in ascorbic acid 1% , 0,2% citric acid or CaCl2 (0,1%).

2. After dipping, reduce oxygen avaiability (MAP) using an equilibrium modified atomsphere packaging. This requires the use of proper film packaging basing on respiration rate of the commodity at the storage temperature chosen.

3. alternative to dipping, using a edible coating (ex., carboxymethtlcellulose based film with additives (antioxidant, acidulant, preservative).

If they are true berries, they have an exocarp (thin skin that may have a protective action)you may try ultrasound combined with heat at lower temperatures or hurdle combinations using pH as one of the conditions

Many thank for all contributors !!

Rapid freezing and storage at low temperatures inactivate enzymes, but in any case the tissue will damage. Irradiation with rays such as gamma ray is somewhat effective.

use 0.5 % H2O2 and 0.5% ascorbic acid in combination.

Irradiation, dipping in organic acid, modified storage condition etc may be useful

You can opt for High Pressure Processing of the berries...there is only is slight increase in temp. which too can be controlled by attaching separate temp. controlling device.

If you have high-pressure processing facility you can use it and you can inactivate at 20C however the pre.surre will be higher

High hydrostatic pressure treatment (50-400 MPa) combined with mild heat treatment (20-60 degrees C) may effects on peroxidase (POD), polyphenoloxidase (PPO) and pectin methylesterase (PME) activities. Optimal inactivation of POD was using 230 Mpa and 43 °C in strawberry puree. Please check publication from Cano,M.P.et alii, 1997, "High pressure and temperature effects on enzyme inactivation in strawberry and orange products".

L-cysteine (0,5% in most cases) is reported in several papers to prevent browning in post-harvest, better if it is combined with a proper packaging (Equilibrium MAP with low oxygen, relatively high CO2, low temperature). It acts directly as an inihibitor of PPO enzymes, also converts o-diphenols to monophenols, thus avoiding their conversions to o-chinones, which polymerize to melanins.

As other people indicate it depends on the enzymes you want to inactivate - also if these berries are for human food consumption this needs to be considered when treating with chemicals

Immerse them for a few hours in brown seaweeds liquid plain concentrated extract. Extract is made using plain tap water 100 gms. of it vs.1 kg of fresh brown sea weeds & macerate them until only plain liquid is got. Though the treatment will not totally inactive the enzymes,but will slow down its rate of action to appreciably high levels. This I have tried on green lemons,making them ripen after 10-15 days,instead of three to four days.

Irradiation, High hydrostatic pressure treatment and freezing can used