Stages of Fruit Development. Maturation The stage of development leading to the attainment of physiological or horticultural maturity.

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1 Fruit Preparation for Consumers Stages of Fruit Development Stages of Fruit Development Maturation The stage of development leading to the attainment of physiological or horticultural maturity. Physiological maturity The stage when a plant or plant part will continue developing even if detached. Horticultural maturity The stage of development when a plant or plant part possesses the prerequisites for utilization by consumers for a particular purpose. John O Neill 1

2 Stages of Fruit Development Ripening The set of processes that occur from the later stages of growth and development through the early stages of senescence and that results in characteristic aesthetic and/or eating quality, as evidenced by changes in composition, color, texture, or other sensory attributes. John O Neill Relative Values Red color Yellow color Aroma Flavor Sugars Soluble pectins Polymerized tannins Green color Acidity Starches Flesh firmness Insoluble pectins Unpolymerized tannins Time Ripening Changes Mature Ripe 2

3 Interviewing Consumers : In Store Consumer Tests Ripening Effect on Consumer Acceptance of Fresh Fruit Crops Mature Figs Ripened Figs Fruit Species Mature Peaches Ripe Peaches Mature Kiwi Ripened Kiwi Acceptance (%) Maturity and Ripening Group 1: Fruits that are not capable of continuing their ripening process once removed from the plant. Blackberry Loquat Pomegranate Cherry Lychee Prickly pear Grape Mandarin Rambutan Grapefruit Muskmelons Raspberry Lemon Orange Strawberry Lime Pepper (bell) Tamarillo Longan Pineapple Watermelon 3

4 Group 1 Raspberry Strawberry Cherry Blueberry Maturity and Ripeness Stages of Strawberries Strawberries must be picked fully-ripe because they do not continue to ripen (improve in flavor) after harvest Optimal harvest stage Group 2: Climacteric Fruits: Fruits that can be harvested and ripened off the plant Apple Mango Persimmon Apricot Nectarine Plum Avocado Papaya Quince Banana Passion fruit Sapodilla Cherimoya Peach Sapote Guava Pear Tomato Kiwifruit Pepper (chili) 4

5 Maturity and Ripeness Stages of Apricots Optimal harvest stages for good flavor Controlled Ripening (43% Mealy) (0% Mealy) 0ºC 20 Days (100% Mealy) 20ºC 48 Hours + 0ºC 20 Days` (0% Mealy) 5ºC 20 Days 20ºC 48 Hours + 5ºC 20 Days Crisosto, Carlos H., David Garner, Harry L. Andris, and Kevin R. Day. Controlled delayed cooling extends peach market life. HortTechnology 14: Ripening Conditions for Some Commonly Ripened Fruit Fruit Exposure time (hours) 1 To 100ppm ethylene Range of ripening temperatures 2 Avocado ºC / 59-68ºF Banana ºC / 58-65ºF Kiwifruit ºC / 54-77ºF Mango ºC / 68-77ºF Pear ºC / 68-77ºF Tomato ºC / 65-68ºF 1 Shorter duration for more mature fruit 2 Faster ripening rate at higher temperatures 5

6 Ripening Conditions for Bananas Fruit temperature: 14 to 18 C (58-65 F) Relative humidity: 90-95% Ethylene concentration: Duration of exposure to ethylene: Carbon dioxide: 100 ppm hours Adequate air exchange to prevent accumulation of CO 2 above 1% Optimal Conditions for Ripening Fruits Ripening rooms Temperature (15-25ºC / 59-77ºF) Relative humidity (85-95%) Air circulation (more uniform temperature and ethylene concentration) Ventilation (introduction of fresh air to keep carbon dioxide below 1%) Treatment with ethylene 100 ppm ethylene in air for 1-3 days, depending on maturity stage at harvest Ripening Facilities Citrus degreening Conventional Forced air 6

7 Forced Air Exposing mature-green bananas for: 1 hour at 50 o F 5 hours at 53 o F 24 hours at 54 o F 72 hours at 55 o F Heat damage 95 o F and chilling damage 56 F Chilling Injury Symptoms Bronzing of Fingers (dull color) Discoloration on inner side of peel Other symptoms: failure to ripen; flesh browning (in severe cases) 7

8 Ripening Room Conditions o F 80-90% RH Low Air Velocity LOCATION Transport Ripening Ethylene is Required to Induce Banana Ripening 8

9 How to apply Ethylene? Ethylene Ethylene Damage Critical Levels = 0.1 to 1 ppm Note the 5- Fold Increase in Respiration Rate (Carbon dioxide production) as Bananas Ripen from Stage 1 or 2 to Stage 4. 9

10 Carbon dioxide reduces efficacy of ethylene in inducing fruit ripening 80% RH Astringency Removal Persimmon Cultivars 10

11 Astringent Removal Astringent Removal 11

12 A closer look at astringency Astringency in persimmons is caused by water-soluble tannins. Tannins are polymers of Pro-Anthocyanidins (PAs) with high molecular weight (~1.38 x 10 4 Da on average in persimmon). PAs consist of flavan-3-ol units that are synthesized via the general pheylpropanoid pathway (the same pathway that produces flavonols and anthocyanin pigments). A closer look at astringency Loss of astringency is caused by the polymerization of water-soluble tannins, resulting in their insolubilization. Treatment with ethanol results in the formation of acetaldehyde in the fruit. Insolubilization of tannins is caused by condensation with acetaldehyde. Ethanol ADH Acetaldehyde Polymerized, insoluble tannins Soluble tannins Tanaka et al.,

13 Loss of astringency in persimmons increases with temperature Ethanol is used to remove astringency in persimmons Carbon dioxide treatment removes astringency of persimmons 13

14 What is degreening? The process of exposing green citrus fruit with low levels of ethylene to enhance coloration Ethylene Degreening Recommended Conditions Ethylene: 1-5 ppm Temperature: 20-21C (68-70 F) in CA 28-29C (82-84 F) in FL Humidity: 90-95% Ventilation: 1 air exchange/hour Carbon Dioxide:reports varies, <1% Early season Mandarins navel oranges Re-greened Valencia oranges Lemons Mandarins Oranges Lemons 14

15 Chlorophylls Photosynthetic carotenoids NON-Photosynthetic carotenoids Thylakoids Chloroplast Thomson 66 Chromoplast From K. Inoue, UCD Degreening with ethylene induces the conversion of chloroplasts to chromoplast and is dependent on: Initial Peel color Temperature Duration of exposure From I. Eaks Coloration stops when C 2 H 4 is stopped Problems that you can find at the retail level in spite of doing it right 15

16 Postripening Management Temperature and softening rate Chilling injury susceptibility Move fruit as quickly as possible to end user Periodically visit your end user to assess fruit quality and how you are doing Relationship between temperature and flesh softening on firm kiwifruit (6-9 lb) stored for more than 5 weeks to manage temperature ripening at shipping, retail, wholesale and store point. Firmness (lb) F 55 F 68 F Days Effect of Temperature on Deterioration of Bananas 16