Role of Acids in Indian Pickles How to acidify

Acid in Food. Natural acidifiers Lime Juice Vinegar. Food Acidification

Acid prevents the growth of spores of deadly botulism bacteria.

Acids control growth of micro-organisms, maintain taste and texture of foods being pickled. Acidity is measured by the pH level. pH level of 7 is neutral. pH level below 7 is acid, over 7 is alkaline. Microorganisms grow best when pH level ranges from 6.5 to 7.5. Yeast and mould grow on a wider range. Few pathogens grow below pH 4.6

pH level of Foods

Acid and acidified foods inhibits growth of Clostridium botulinum. You need a pasteurizing heat treatment to destroy bacteria, viruses, yeasts, and mold.

Antimicrobial effectiveness is a function of acids, spices, salt, sugar, oil and moisture level in the pickle.

Food Classifications

There are 4 categories of foods based on the amount of acid.

High Acid Foods

The pH level is 3.7 or lower. Example of these items are: Limes, Lemons

Acidification is not required.

Acid Foods

The pH level of these foods ranges 3.7 to 4.6. Example of these items include: Oranges and Tomatoes.

Acidification may be required depending on the variety

Medium Acid foods

The pH level of these foods ranges 4.6 to 5.3. Examples: Cheese Carrots

Should be Acidified

Low Acid

The pH level of these foods is over 5.3. Examples: Meat Fish and most of the vegetables

Must be Acidified

Acidifying agents

In India, natural acidifying agents used are: Amchoor, Tamarind, Sumac, Pomegranate seeds, Dahi, Fresh Lime juice, home made sugar-cane and coconut vinegars. Sumac is becoming a hard-to-find spice. Curing with salt also adds to acid level slightly

Pomegranate has Ellagic acids

Sumac has Malic Citric and Tatric acid

Dahi has lactic acid. Fresh Dahi has a pH level of 4.6 that drops to 4.4 as it gets sour.

Tamarind has about 20% tartaric acid.

Amchoor (dried raw tart mango) has Oxalic, Citric, Malic and Succinic acids. Ripened fruits are high in Tartaric and Malic acids with a trace of Citric acid

Limes have slightly lower pH level than Lemons. Practically, both lime and lemon juices have approximately 5% citric acid. The pH level for limes is 2 and for lemons it is about 2.3.

Homemade Sugar-cane and coconut vinegars used in India have Acetic acid ranging from 4% to 18%

Vinegar

Modern recipes use vinegars with 5% acetic acid (pH level of 2.4). Distilled white vinegar has a sharp acid taste. mild aroma. does not effect the color. Cider vinegar is made by fermenting Apples, It has acetic acid, fruit acids, esters, and inorganic salts. The flavor is fruity and matches well with fruits and vegetable being pickled. Cider vinegar darken the pickles.

2 Tablespoons of Vinegar (5% acetic acid) is dispersed uniformly all through in one cup of Pickle.

How to acidify foods?

Typical Indian pickle consists of Exemplar (item to be pickled), spices, liquid acid, and oil.

Normally, the liquid acid is Lime Juice (5% citric acid), and or the Vinegar (5% Acetic acid)

Oils used are mustard canola peanut sesame.

The spices may also have acids such as Amchoor, Tamarind.

Acidification involves 4 steps

1. Treat oil

You can all the oils as they are except for Mustard oil. Mustard oil should be heat treated to control pungency. Heat mustard oil in a pan to smoking point. As soon as the oils starts to smoke, shut off heat and let it cool down to room temperature. Set aside

2. Prepare Acid Mix

Mix Liquid Acid (Vinegar and or Lime Juice) and spices. Bring it to a boil.

3. Acidify Food

Add Exemplar. Adjust heat so that temperature is 180º F. Simmer for 5 minutes. Shut off heat and let it cool to room temperature. Remember there is only about ¾ cup of liquid for 2 pounds of exemplar and spices. You will have to use spatula to coat and spread on the exemplar.

Heating mixture to 180º F, destroys existing vegetative bacteria, yeast and molds. The exemplar does not become soft if the temperature is kept at or below 185º F,

4. Add Oil

Add oil.

Oil should not be added before the exemplar has been acidified

Oil coats the food creating a barrier to acidification and oxygen making it highly susceptible to growth of botulism bacteria

Can we test for pH level at home?

Stir the pickle, remove about 1 Tablespoon of pickle fluid and use litmus paper to check the pH level.