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Avocados are unique in the amount of oil they contain and that they will not ripen on the tree. The key storage limitations after >≈4 weeks is flesh graying (or diffuse flesh discoloration), and stem end and body rots. Optimum storage temperature is ≈ 5–6°C where irregular skin blackening is a chilling response at low temperature (

Avocados are a subtropical climacteric fruit that is generally oblong in shape and green skinned, although ‘Hass’, the dominant commercial cultivar, ripens to purple-black. They are one of the few fruits that contain significant amounts of oils (fatty acids). The high concentrations of monounsaturated fatty acids and other phytochemicals make avocado a very healthy and nutritious fruit. Avocados do not ripen unless removed from the tree, meaning fruit can be mature but ‘tree stored’ for as long as 12 months. Increased commercial maturity is associated with increased fruit size, oil and dry matter content, and decreased ripening times. Avocados have a relatively short storage life, limited primarily by the expression of internal chilling injury (CI) symptoms, but rots are a limitation for fruit grown in many countries. Optimum storage temperature is generally around 6 °C, and temperatures below 3 to 4 °C (depending on cultivar and time in the season) lead to external CI (skin blackening). Controlled atmosphere storage and 1-MCP (SmartFreshSM) are effective commercial tools for improving storage life. Since avocado cannot be consumed unripe, an increasingly important commercial tool is the use of ethylene to hasten and synchronize ripening. New processing options, such as cold-pressed oil extraction and high-pressure processing, are receiving increasing attention.

Persimmons are temperate, climacteric fruit, externally attractive with very little acidity and primarily sweet flavour. Maturation involves colour changing from green to yellow-orange or red, accompanied by increased soluble solids content (SSC), reduced fruit firmness and astringency. Commercial maturity is generally determined by colour. Persimmon’s unique characteristic is a high soluble tannin content, responsible for astringency, which may or may not decline with maturation. Thus, cultivars are differentiated by the presence of low astringency (in ‘sweet’ persimmons), or extreme astringency, lost naturally with fruit softening. Treatments to remove astringency are generally applied postharvest, mostly using high CO 2 . Optimum storage is generally at 0 °C, but higher temperatures may result in chilling injury. 1-MCP and modified/controlled atmosphere storage (MA/CA) can extend storage duration to three months. Most external disorders are expressed as skin blackening, and pathological disorders are generally low unless storage exceeds two months.

Feijoa is a climacteric fruit that needs to remain on the tree up to the point of natural fruit drop to attain its typical texture and strong aroma. Identifying horticultural maturity is difficult and mixed maturities at harvest can cause significant problems in later storage because of heterogeneity. Feijoas can be stored for up to four weeks at 4 °C depending on the cultivar, with the end of storage life predominantly determined by flavour loss and internal browning. External changes during storage are limited except for shrivelling due to water loss, a slight change in flesh colour and appearance of symptoms resulting from bruising during harvesting and postharvest handling. The main storage disorders reported are chilling injury and CO2 damage.

The tamarillo is a subtropical non-climacteric fruit that produces fruit throughout the year, with fruit production peaking in late summer or autumn. The fruit has an attractive deep red skin and flesh, and a distinctive somewhat acidic flavour. Tamarillos are optimally stored at 3 to 4.5 °C, and 90–95% relative humidity. Lower temperatures will increase the risk of chilling injury. As the fruit mature, the colour changes from green to purple, red, amber and gold, while firmness and titratable acidity decline and the juice yield, soluble solids content (mainly sugars) and pH increase. Stem and calyx quality are important factors from a commercial marketing perspective although they do not affect flavour.

Publisher Summary Avocado (Persea americana Mil.) is a subtropical tree that is relatively frost-sensitive and grows to a height of 5–30 m. The fleshy fruit are borne yearly from the current season's wood and the green fruit ripen only after being harvested. Avocado oil is obtained from the flesh fruit and is a relatively new arrival in culinary circles. The predominant uses of avocado oil are in the cosmetic industry because of its stability and high level of vitamin E (α-tocopherol). The bulk of avocado oil is extracted by relatively harsh methods like high temperature and solvent extraction, typically followed by standard refining steps. The ultimate market of the oil generally dictates the fruit quality required. For the production of good-quality cold-pressed oil, the fruit must be relatively sound with mainly cosmetic-quality issues or too small for sale. Cold-pressed avocado oil is a new product with significant production, commercialization, and marketing only occurring in the 21st century. Avocado oil is a high-value oil with excellent qualities for both culinary and cosmetic uses.

Publisher Summary The membrane bilayer and its surface interactions have been pictured as an electrical equivalent circuit with varying properties such as channel type, Nernst potentials describing reversal potentials, and the membrane capacitance. This chapter presents the computational models to study electrified potential of a bilayer. The membrane is viewed to have dielectric heterogeneity and to be a fluid mosaic adorned with various proteins, carbohydrates, and ion associations. There are two approaches to handling this heterogeneous type of environment: continuum and molecular theories. The continuum model assumes that the bulk properties of the system such as dielectric constant and density of solvent hold true on the molecular level. The simplest continuum model is the implicit dielectric sandwich model. The simple continuum model has some advantages such as reduced computational time. However, it has obvious limitations in terms of understanding membrane surface properties. In order to incorporate these properties and thus enhance the success of the model, one needs to review the following notion. When there is a charged surface, such as the headgroup region of a lipid bilayer, solvent molecules, especially ions, will segregate and perform one of two functions. The counterions will associate with the headgroup region to equally balance the surface or the counterions will build up in between the two surfaces and mix with the rest of the solvent molecules. This segregation of ions leads to what is commonly referred to as the electrical double bilayer. The chapter also examines how this electrical double layer is incorporated into biological systems through various methods and bridges the gap between the simple dielectric sandwich model and molecular calculations.