Fruits stored in a cold chamber exhibit longer storage life because
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- Aexposure to sunlight is prevented
- Bconcentration of carbon diodixe in the environment in increased
- Crate of respiration in decreased
- Dthere is an increase in humidity
Show answer
Answer: (C) rate of respiration in decreased
Fruits are living organisms that continue to respire (breathe) even after being harvested.
During respiration, they consume their stored sugars and starches, producing CO₂, water, and heat — this process drives ripening and eventually spoilage.
Cold chambers work by lowering the temperature, which directly slows down the rate of respiration.
When respiration slows, the fruit uses up its stored food more slowly, ripens more gradually, and therefore lasts longer.
Option (a) — sunlight prevention is not the primary reason.
Option (b) — CO₂ concentration is not the main mechanism in simple cold storage.
Option (d) — humidity may help prevent drying but is not the main reason for longer shelf life.
Cold storage slows down fruit respiration, which is the biological process that consumes stored sugars and causes ripening and spoilage.
This tests basic understanding of plant physiology - that harvested fruits are still living organisms that breathe and metabolize.
Fruit Respiration & Physiology
Science And Technology respiration fruits
Fruit Respiration: How Plants Breathe After Harvest
Fruits continue cellular respiration even after harvest — consuming stored sugars and producing CO₂, water, and heat
Lower temperature = slower respiration rate — this is why cold storage extends shelf life
Respiration drives ripening and spoilage by depleting stored food reserves
Plants respire 24/7 unlike photosynthesis which needs light
Why Fruits Keep 'Breathing'
Harvested fruits are living tissues that need energy to maintain cellular functions. They get this energy through cellular respiration — breaking down stored sugars and starches to produce ATP (cellular energy).
Respiration equation: Stored sugar + Oxygen → CO₂ + Water + Heat + Energy
Respiration to Spoilage Process
%%{init: {"flowchart": {"wrappingWidth": 460}}}%%
flowchart TD
s1["`**Fruit harvested**
Living tissue continues metabolic processes`"]
s2["`**Cellular respiration occurs**
Stored sugars/starches broken down for energy`"]
s3["`**Food reserves depleted**
Fruit texture, flavor, and nutrition decline`"]
s4["`**Ripening accelerates**
Cell walls weaken, enzymes activate`"]
s5["`**Spoilage begins**
Tissue breakdown, bacterial/fungal growth`"]
s1 --> s2
s2 --> s3
s3 --> s4
s4 --> s5Key Facts About Plant Respiration
Temperature dependency: Every 10°C increase roughly doubles respiration rate
24-hour process: Unlike photosynthesis, respiration continues day and night
Heat production: Respiring fruits generate heat, which can accelerate spoilage if not removed
Oxygen requirement: Most fruits need oxygen for aerobic respiration
Species variation: Tropical fruits generally have higher respiration rates than temperate fruits
Trap: Confusing respiration with photosynthesis — fruits don't photosynthesize after harvest
Trap: Thinking sunlight exposure is the main spoilage factor — respiration occurs regardless of light
Trap: Assuming CO₂ increase is the mechanism — it's a result of slower respiration, not the cause
Trap: Mixing up humidity effects — while important, humidity control doesn't slow respiration itself
Cold Storage Technology
Science And Technology cold chamber storage
Cold Storage: Science Behind Extended Shelf Life
Cold storage works by slowing metabolic processes — primarily respiration in fruits and vegetables
Optimal temperatures: 0-4°C for most fruits, specific ranges for different species
Multi-factor approach: Temperature + humidity + air circulation for best results
Primary Mechanism
Cold storage extends shelf life primarily by reducing metabolic rate. Lower temperatures slow down enzymatic reactions, including cellular respiration, which reduces the rate at which stored food compounds are consumed.
Cold Storage Factors Analysis
Factor | Primary Effect | Mechanism | Importance |
|---|---|---|---|
Low Temperature | Slows respiration | Reduces enzyme activity | Primary mechanism |
Controlled Humidity | Prevents water loss | Reduces transpiration | Secondary benefit |
Air Circulation | Removes heat/gases | Prevents gas buildup | Supporting factor |
Light Prevention | Stops photodegradation | Prevents vitamin breakdown | Minor factor |
Cold Storage Benefits
Slows ripening: Enzymes that soften fruit work slower at low temperatures
Reduces microbial growth: Bacteria and fungi reproduce slower in cold conditions
Preserves nutrition: Vitamins and antioxidants break down more slowly
Maintains texture: Cell wall degradation slows significantly
Storage Temperature Guide
Source: Atlascool — Vegetable cold storage room • cold rooms manufacturer · www.atlascool.com
Option trap: Don't pick humidity or light prevention as primary reasons — temperature is the main factor
Concept trap: CO₂ concentration may be controlled in some storage but isn't the basic mechanism of simple cold storage
Logic trap: All factors may contribute, but UPSC wants the dominant mechanism — slowed respiration
Food Preservation Methods
Science And Technology
Food Preservation: Techniques & Scientific Principles
Primary goal: Slow or stop microbial growth and enzymatic reactions that cause spoilage
Temperature-based methods (cooling/heating) are most common and effective
Combination approaches often work better than single methods
Major Preservation Methods
Method | Mechanism | Examples | Shelf Life Extension |
|---|---|---|---|
Refrigeration | Slows metabolism | Cold storage, chillers | Days to weeks |
Freezing | Stops microbial growth | Frozen foods | Months to years |
Dehydration | Removes water | Dried fruits, jerky | Months to years |
Canning | Heat sterilization | Canned goods | 1-5 years |
Chemical | Antimicrobial agents | Salt, sugar, preservatives | Weeks to months |
Modified Atmosphere | Controls gas composition | CA storage, MAP packaging | Extended fresh period |
Preservation Science Principles
# Food Preservation
## Temperature Control
- Refrigeration
- Freezing
- Pasteurization
- Sterilization
## Water Activity
- Dehydration
- Salting
- Sugar curing
- Freeze drying
## Chemical Methods
- Natural preservatives
- Synthetic additives
- pH control
- Antioxidants
## Physical Barriers
- Packaging
- Vacuum sealing
- Modified atmosphere
- IrradiationModern Preservation Trends
Controlled Atmosphere (CA) storage: Adjusts O₂ and CO₂ levels to slow ripening further
Modified Atmosphere Packaging (MAP): Extends retail shelf life using gas-flushed packages
Natural preservatives: Growing preference for plant-based antimicrobials over synthetic chemicals
Cold chain management: Maintaining consistent low temperatures from farm to consumer