Food Canning Techniques Honor

Household Arts

Requirements

1. Describe the following methods for food preservation:
   • Pasteurization
   • Sterilization
   • Tyndallization
   • Appertization (canning)
   • Saline solution (salting)
   • Preserves (compote)

   Answer: 1) Pasteurization: heating to moderate temperatures (about 72°C for 15 seconds, or 63°C for 30 minutes) followed by rapid cooling; it eliminates pathogenic microorganisms without altering the food much, but it does not destroy all spores. 2) Sterilization: prolonged heating to high temperatures (around 121°C) that destroys all microorganisms, including spores, making the food sterile. 3) Tyndallization: discontinuous (repeated) heatings at 60-80°C on successive days; between the heatings the spores germinate and are eliminated in the following stage, sterilizing without damaging the food as much. 4) Appertization: cooking the food already inside a hermetically sealed package (can or jar), which is then heated; it combines heat treatment and sealing to preserve for a long time. 5) Saline solution (salting): preservation through the use of salt, which draws out water by osmosis and creates an environment unfavorable to microorganisms (dry salting or brine). 6) Compote: preservation of fruits in sugar syrup; the sugar reduces the available water and, with cooking and bottling, prevents the development of microorganisms. — Each method acts against different microorganisms. Pasteurization preserves flavor but kills pathogenic bacteria. Total sterilization, used in canned goods, can last 5+ years. Salt and sugar preserve through osmotic dehydration of the bacteria, a technique used for millennia by humanity in home preservation.

2. List the utensils needed to prepare homemade preserves.

   Answer: Utensils: large stainless steel pots, jars with airtight lids (canning jars), funnel, ladle, tongs for hot jars, sieve, wooden spoons, sharp knife, cutting board, scale, new lids, and a culinary thermometer. — Jars should be sterilized in boiling water for 15 min before use. Lids need to be new to ensure a vacuum seal. Stainless steel is preferred because it does not react with acids. The thermometer ensures the correct temperature for pasteurization (72°C) or appertization (121°C with pressure).

3. What are the techniques for cleaning:
   • Food
   • Utensils
   • Work surface

   Answer: 1) Foods: wash under running water, scrub with a brush when necessary, and soak in a chlorinated solution (about 1 tablespoon of unscented bleach per liter of water) for 15 minutes, then rinse. 2) Utensils: wash with water and detergent, removing residues, and disinfect by boiling for 15 minutes or by immersion in a chlorinated solution, letting them dry naturally. 3) Work surface: remove food scraps, wash with water and detergent, and disinfect the counter with a chlorinated solution or 70% alcohol, keeping it dry and clean before and after handling the foods. — The chlorinated solution (200 ppm) is the Anvisa standard for sanitization. 70% alcohol is more effective than 90% because it penetrates bacteria better. A brush helps with leaves like lettuce (which hides bacteria). Porous wooden boards should be replaced regularly — bacteria lodge in the crevices.

4. Make a list of the common foods in your region that are good for making preserves.

   Answer: Fruits: guava, mango, pineapple, jabuticaba, banana. Vegetables: tomato, cucumber, green beans, beetroot, carrot. Greens: cauliflower, broccoli, corn. Others: bell pepper, heart of palm, olive. — Tomato is versatile — it becomes sauce, pickles, or sun-dried. Fruits high in pectin (guava, apple, jabuticaba) become natural jelly without needing a thickener. Young cucumbers make crunchy pickles. Seasonality reduces cost: buying in season and making preserves is savings that last all year.

5. Demonstrate how to select, peel, and chop the foods to prepare the preserve.

   Answer: Select: discard bruised, rotten, or unripe foods. Peel with a sharp knife, removing only the skin, without wasting the pulp. Chop uniformly (cubes of the same size cook evenly). — Unripe foods have a sour taste; overripe ones ferment. Uniform cuts (standard 1 cm cubes) ensure even cooking. Clean hands and gloves prevent contamination by Salmonella or E. coli. A dull knife crushes instead of cutting, harming the texture and the final appearance of the finished product.

6. Demonstrate how to sterilize, fill, seal, and test whether the jars are well sealed.

   Answer: Sterilize jars and lids in boiling water for 15 min. Fill the jars with the hot cooked foods, leaving 1 cm of free space. Close the new lid tightly and place it in a water bath for 20 min. — The vacuum happens when the air inside the jar cools and contracts, pulling on the lid. A sign of a well-made vacuum: a concave lid and a metallic sound when you listen. Overfilled jars can burst from internal pressure. A free space of 1 cm is the international standard for safe preserves.

7. How do you hermetically or vacuum seal a jar of preserves at home?

   Answer: Fill the jar with the hot contents to 1 cm from the rim, close it with a new metal lid, and place it in a water bath for 15-20 min covered. As it cools, the internal steam condenses and creates a natural vacuum — the lid becomes concave and does not give way to the touch. — This method is called 'water-bath sealing' and has been used for more than 100 years. Lids with a rubber seal (TWIST type) ensure a better seal. Electric vacuum devices cost R$ 200+ but the water bath is free and works. Indicator of a perfect seal: a 'pop' when opening.

8. What is pectin? When should it be used?

   Answer: Pectin is a natural fiber found in fruits (apple, quince, jabuticaba) that gives a gelatinous consistency. Use it when making jellies and fruit preserves with little natural pectin (strawberry, pineapple). — Pectin is a polysaccharide from the cell walls of fruits. Green apple has more pectin than ripe. Fruits like pineapple and strawberry need extra pectin to become a consistent jelly. In powder form, it usually comes with 'invert sugar' to activate it — read the label to use the right amount.

9. What are the signs that a preserve is no longer suitable for consumption?

   Answer: Signs: a bulging lid (internal air = bacteria), cloudy liquid, visible mold, a sour or fermented smell, a change in color, bubbles in the contents. With any of these, discard it without tasting. — Botulism causes progressive muscle paralysis. The bacterium Clostridium botulinum produces a deadly toxin in oxygen-free environments (a poorly made vacuum). A sour smell is fermentation by yeasts, less dangerous but it spoils the product. When in doubt, throw it away — health is worth more than the contents.

10. What is botulism? What is it caused by? What are the signs and symptoms of this disease?

    Answer: Botulism is a serious disease caused by the toxin of the bacterium Clostridium botulinum in poorly processed preserves (a deficient vacuum). Symptoms: double vision, difficulty swallowing, slurred speech, progressive descending muscle paralysis, and respiratory arrest. — Botulinum toxin is one of the most lethal known — 1 gram could kill 1 million people. Curiously, in microdoses it is the famous 'Botox' used in aesthetics. Symptoms begin 12-36h after ingestion. Antitoxin must be applied quickly. Poorly made homemade preserves are the main cause in Brazil.

11. Make two of the following preserves and present them to the instructor for tasting:
    • Fruit juice
    • Vegetable or greens
    • Fruit
    • Preserve or jelly

    Answer: Choose 2 preserves (e.g., strawberry jelly and cucumber pickles), carry out the whole process (select, wash, cook, sterilize jars, fill, water bath, seal). — Strawberry jelly traditionally uses 1:1 fruit:sugar, but it can be reduced to 1:0.7 with pectin. Cucumber pickles need a brine (1L water + 1 tbsp salt + 200ml vinegar). Labeling is important for sanitary reasons — knowing the date allows you to assess a safe shelf life over the next 6-12 months.