Review
Effects of superatmospheric oxygen levels on postharvest physiology and quality of fresh fruits and vegetables

https://doi.org/10.1016/S0925-5214(00)00122-8Get rights and content

Abstract

Exposure to superatmospheric O2 concentration may stimulate, have no effect, or reduce rates of respiration and ethylene production, depending on the commodity, maturity and ripeness stage, O2 concentration, storage time and temperature, and concentrations of CO2 and C2H4 present in the atmosphere. In some plant organs, cyanide-resistant respiration is enhanced by elevated O2 atmospheres. Ripening of mature-green, climacteric fruits was slightly enhanced by exposure to 30–80 kPa O2, but levels above 80 kPa retarded their ripening and caused O2 toxicity disorders on some fruits. High O2 concentrations enhance some of the effects of ethylene on fresh fruits and vegetables, including ripening, senescence, and ethylene-induced physiological disorders (such as bitterness of carrots and russet spotting on lettuce). While superatmospheric O2 concentrations inhibit the growth of some bacteria and fungi, they are much more effective if combined with elevated (15–20 kPa) CO2, which is a fungistatic gas.

Introduction

Oxygen concentrations greater than 21 kPa (induced through high O2 atmospheres or hyperbaric atmospheres) may influence postharvest physiology and quality maintenance of fresh horticultural perishables either directly or indirectly via altered CO2 and C2H4 production rates. Increased O2 concentrations around and within the commodity result in higher levels of free radicals that can damage plant tissues (Fridovich, 1986). Sensitivity to O2 toxicity varies among species and developmental stages.

Day (1996) discussed the rationale behind, and the potential applications for, the use of novel gas mixtures (i.e. high oxygen, argon, and nitrous oxide) for the modified atmosphere packaging (MAP) of fresh prepared produce. He stated that high O2 levels are effective at inhibiting enzymic discoloration, preventing anaerobic fermentation reactions, and influencing aerobic and anaerobic microbial growth.

Oxygen is colorless, odorless, and tasteless, so O2 enrichment cannot be detected by the human senses. Superatmospheric O2 levels can accelerate combustion of all materials. Thus, special care must be taken in designing and using packaging machines and gas-flushing systems to avoid ignition sources when high O2 concentrations are utilized (British Compressed Gases Association, 1998).

In this report we will review published information and some unpublished data on responses of fresh fruits and vegetables to superatmospheric O2 concentrations alone and in combination with elevated CO2 atmospheres.

Section snippets

Respiratory metabolism

Exposure to superatmospheric O2 levels may stimulate, have no effect, or reduce rates of respiration, depending on the commodity, maturity and ripeness stage, O2 concentration, time and temperature of storage, and the CO2 and C2H4 concentrations. Kidd and West, 1925, Blackman, 1928, Blackman and Parija, 1928 were among the first to describe the intricate relationship between apple ripening, O2 tension and respiratory activity. Kidd and West (1934) found that 100 kPa O2 accelerated the onset of

Ethylene biosynthesis and action

Creech et al. (1973) reported that ‘Russet Burbank’ potato tubers stored in 80 kPa O2+12 kPa CO2 produced ethylene at a much higher rate than those kept in air at 7°C. ‘Bartlett’ pears kept in 100 kPa O2 and 20°C had higher rates of ethylene production, chlorophyll degradation, and softening than those kept in air (Frenkel, 1975). Morris and Kader (1975) reported that 30 and 50 kPa O2 atmospheres accelerated ethylene production and ripening of mature-green and breaker tomatoes stored at 20°C.

Pigments and color

Biale and Young (1947) reported that the change in lemon color from green to yellow was markedly accelerated by high O2 levels. However, exposure to 99.2 kPa O2 also induced rapid peel breakdown. At 18°C, cherries and apricots held in 100 kPa O2 were slightly less ripe (as indicated by color) at the end of 10 days than those held in air (Claypool and Allen, 1948). Oxygen at 30, 50, and 75 kPa hastened ‘Wickson’ plum ripening at 20°C, while 100 kPa O2 delayed color changes associated with

Growth and development

The potential effects of superatmospheric O2 levels on elongation and curvature of asparagus and sprouting of onions and potatoes should be investigated in view of the findings of Abdel-Rahman and Isenberg (1974) that 40 kPa O2 increased sprouting and rooting of 0°C-stored carrots.

Physiological disorders

Kidd and West (1934) showed that storage of ‘Bramley's Seedling’ apples in 100 kPa O2 can be detrimental. After 4 months at 4°C, symptoms included mealy flesh and browning of skin and flesh. Storage of ‘Granny Smith’ apples in 70 kPa O2 at 0°C for 1 month did not accelerate the severity of sunscald (Lurie et al., 1991). Solomos et al. (1997) reported that ‘Gala’ and ‘Granny Smith’ apples exposed to 100 kPa O2 developed extensive injury akin to that which occurs under 1 kPa or lower O2

Responses of microorganisms

Growth rate and growth efficiency as well as the respiration rates of living organisms are dependent on O2 tension (Harrison, 1976). Above the ‘critical level’ in air these parameters are not affected by the O2 concentration, but growth is inhibited below the critical level as well as at toxic high O2 tensions. Obligate anaerobes are injured even by 0.1 kPa O2 concentrations.

Bert (1878) reported that compressed air at 15–44 atmospheres preserved meat and raw eggs for several days at room

Future research needs

It is clear from the limited published information on effects of elevated O2 levels on postharvest physiology and quality of fresh fruits and vegetables that much more research is needed to answer the following questions:

  • 1.

    What are the mechanisms by which superatmospheric O2 levels influence rates of CO2 and C2H4 production by climacteric fruits, non-climacteric fruits, and non-fruit vegetables?

  • 2.

    Do high O2 atmospheres ameliorate or aggravate chilling injury and other physiological disorders?

  • 3.

    Can

Acknowledgements

We thank Beth Mitcham, Mikal Saltviet, and Annette Wszelaki for their critical review of this manuscript.

References (64)

  • J. Barker et al.

    The ascorbic acid content of potato tubers. III. The influence of storage in nitrogen, air and pure oxygen

    New Phytol.

    (1952)
  • J. Barker et al.

    Studies in the respiratory and carbohydrate metabolism of plant tissues. VII. Experimental studies with potato tubers of an inhibition of the respiration and of a ‘block’ in the tricarboxylic acid cycle induced by ‘oxygen poisoning’

    Proc. R. Soc. London Ser. B

    (1955)
  • J.W. Bean

    Effects of oxygen at increased pressure

    Physiol. Rev.

    (1945)
  • P. Bert

    Barometric pressure. Researches in experimental physiology. Paris

    (1878)
  • J.B. Biale

    Effect of oxygen concentration on respiration of the Fuerte avocado fruit

    Am. J. Bot.

    (1946)
  • J.B. Biale et al.

    Critical oxygen concentrations for the respiration of lemons

    Am. J. Bot.

    (1947)
  • F.F. Blackman et al.

    Analytic studies in plant respiration. I. The respiration of a population of senescent ripening apples

    Proc. R. Soc. London Ser. B

    (1928)
  • F.F. Blackman

    Analytic studies in plant respiration. III. Formulation of a catalytic system for the repsiration of apples and its relation to oxygen

    Proc. R. Soc. London Ser. B

    (1928)
  • The safe application of oxygen enriched atmospheres when packaging food

    (1998)
  • R.W. Buescher et al.

    Color development and carotenoid levels in rin and nor tomatoes as influenced by ethephon, light and oxygen

    J. Food Sci.

    (1978)
  • W.G. Burton

    Some biophysical principles underlying the controlled atmosphere storage of plant material

    Ann. Appl. Biol.

    (1974)
  • J. Caldwell

    Effects of high partial pressures of oxygen on fungi and bacteria

    Nature

    (1965)
  • C. Chin et al.

    Influence of ethylene and oxygen on respiration and peroxide formation in potato tubers

    Nature

    (1976)
  • J.K. Choudhury

    Researches on plant respiration. V. On the respiration of some storage organs in different oxygen concentrations

    Proc. R. Soc. London Ser. B

    (1939)
  • L.L. Claypool et al.

    Carbon dioxide production of deciduous fruits held at different oxygen levels during transit periods

    Proc. Am. Soc. Hort. Sci.

    (1948)
  • L.L. Claypool et al.

    The influence of temperature and oxygen level on the respiration and ripening of Wickson plums

    Hilgardia

    (1951)
  • D.L. Creech et al.

    The influence of storage factors on endogenous ethylene production by potato tubers

    Am. Potato J.

    (1973)
  • B.P.F. Day

    High oxygen modified atmosphere packaging for fresh prepared produce

    Postharv. News Info.

    (1996)
  • B.P.F. Day et al.

    Novel modified atmosphere packaging (MAP) for fresh prepared produce

    (1998)
  • B. Demple et al.

    Inducible repair of oxidative DNA damage in E. coli

    Nature

    (1983)
  • C. Frenkel

    Oxidative turnover of auxins in relation to the onset of ripening in Bartlett pear

    Plant Physiol.

    (1975)
  • C. Frenkel et al.

    Initiation of lycopene synthesis in the tomato mutant rin as influenced by oxygen and ethylene interactions

    HortScience

    (1976)
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      For example, high oxygen concentration significantly increased the respiration rate of lemon fruit (Biale and Young, 1947), while similar concentrations decreased the respiration rate of ‘Spartan’ apples (Lu and Toivonen, 2000) and mushrooms (Li et al., 2017). In fruit and vegetables, respiration provides energy for life activities and physicochemical reactions (Kader and Ben-Yehoshua, 2000; Li et al., 2017); however, a high respiration rate accelerates metabolite consumption to senescence and aging (Li et al., 2016). Senescence or browning of harvested horticultural products is associated with limited energy availability (Jiang et al., 2007).

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