Advances in Plants & Agriculture Research Review Article Open Access Kiwifruit, a botany, chemical and sensory approach a review Abstract Volume 8 Issue 6 - 2018 The kiwi is a fruit with a great agricultural, botanical, and economic interest. Teresa Pinto, Alice Vilela Originally from China, this species is currently widespread in practically all the Department of Biology and Environment, University of Trás-os- world, due to the high nutritional value of the fruits, excellent organoleptic qualities Montes and Alto Douro, Portugal besides therapeutic benefits in the health. The most common kiwifruit species grown commercially is Actinidia deliciosa even though many varieties of this fruit are Correspondence: T Pinto, University of Trás-os-Montes and produced by other cultivars or by another kind of plants, such as Actinidia chinensis Alto Douro, Biology and Environment Department, Centre and the Actinidia kolomikta or the Actinidia argute. Although there are many varieties for the Research and Technology of Agro-Environmental and in this species, the A. deliciosa Hayward cultivar is the most popular variety marketed Biological Sciences (CITAB), 5001 801 Vila Real, Portugal, commercially. Kiwifruits contain aromatic compounds able to attract consumers due Email to their palatability. The esters, ethyl butanoate and methyl benzoate and the aldehyde E-2-hexenal, were shown to increase “characteristic kiwifruit aroma and flavor”. All Received: July 04, 2018 | Published: November 17, 2018 these characteristics are appreciated by the kiwi-consumers. Several preservation techniques have now been used to augment kiwi shelf life, including cold storage, chemical dipping, modified atmosphere packaging and edible coatings, making it possible for the consumers to enjoin the fruit all the year. Keywords: kiwifruit, Actinidia, kiwi cultivars, bioactive compounds, sensory characteristics Introduction Indeed, this fruit is widespread throughout the world, due to his high nutritional value, with high levels of vitamin C, besides the excellent Kiwi - history, producer countries and health benefits organoleptic qualities, associated with its adaptability to temperate 4‒8 Kiwifruit is botanically known as Actinidia deliciosa.1 This species and subtropical climates. Several studies showed that kiwifruit was first found along the border of the Yangtse River valley in China packs more nutrients than other commonly consumed fruit (Figure and later, in 1847 and 1904, the first plants were send for England 2), and highlight its therapeutic benefits in healthy metabolism, iron and America, respectively.2 According to official records, the first content, digestive potential, antioxidant property, immune function commercial plantings were established in New Zealand in 1937. The and also his protective effects against coronary artery disease. As a expansion of this species throughout the world began to take place in the source of ascorbic acid and polyphenols, the kiwifruit aids in lowering 1960s with the export of New Zealand plants and seeds to destinations the risk of arteriosclerosis, cardiovascular diseases, and some forms of cancer,9 in irritable bowel syndrome,10 and also protect the cells in- such as Germany, Italy, Spain, India, South America, Morocco, Israel 11 and South Africa.2 By the 1980’s, other countries around the world vitro from oxidative DNA damage. began to produce and export kiwi. At present, commercial growth of the fruit has spread too many countries including the United States, Italy, Chile, France, Greece, India and Japan. Figure 1 shows the top kiwifruit producing countries in the world.3 Figure 2 Schematicre presentation of Kiwi main nutrients constituents. Kiwi cultivars The genus Actinidia belongs to the family Actinidiaceae, to the order Ericales, to the class Magnoliopsida and to the division 3 Figure 1 Production volume of kiwis worldwide in 2016, by leading country. Magnoliophyta. There are dozens of species comprising the genus Submit Manuscript | http://medcraveonline.com Adv Plants Agric Res. 2018;8(6):383‒390. 383 © 2018 Pinto et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Copyright: Kiwifruit, a botany, chemical and sensory approach a review ©2018 Pinto et al. 384 Actinidia.12 The most common kiwifruit species grown commercially lower productivity and fundamentally because of a much shorter cold is Actinidiadeliciosa (green kiwi), even though many varieties of this storage.13 fruit are produced by other cultivars or by another kind of plants, such as Actinidia chinensis (yellow kiwi) and the Actinidia Kolomikta Male (A. deliciosa) 13 or the Actinidia arguta (baby kiwi). In fact, the world production Most male cultivars have been selected to coincide in flowering of A. arguta already corresponds to 17% of the total kiwi produced with Hayward, the predominant fruiting cultivar. Effective pollination, worldwide, with A. deliciosa and A. chinensis being the most seed set, and full-sized fruit require coincident flowering of males and produced species, with 37% and 31%, respectively, and A. kolomitka females but weather conditions during spring have a major effect on and other inter specific hybrids the species with the lowest world the time of flowering of males, relative to that of Hayward. Different 14 production, with 8% and 7%, respectively. Below are described the males are therefore being selected for the different growing countries. most important varieties of kiwis, the point of view of their production So, there are many cultivars of males available. Examples include and consumption of each type or species. Each variety of kiwifruits Matua, Tomuris, Cal Chico Nº3, Chico Early, and Chico Extra Early.17 has particular characteristics, due to the ability to adapt to the soil and to the local climate conditions. Actinidia chinensis cultivars (yellow kiwi) Actinidia deliciosa cultivars (green kiwi) The fruits of this species cultivars (Table 1) are characterized by having a bright yellow flesh, lower acidity and a greater sweetness Actinidia deliciosa is the most widely cultivated species in the than the green kiwi, what which makes them more desirable in the world. As its name suggests, it has a bright green pulp and an acidic Asian market.13 In the present, the Hort16A (Zespri® Gold) is the taste, which usually has 12 to 14º Brix at the time of consumption. cultivar of this species most cultivated in the world.13 It has exceptional nutritional properties, with very high mineral and vitamin contents, being one of the fruits with the highest content in Hort16A (Zespri® Gold) variety vitamin C. Although there are many varieties in this species (Table Obtained in New Zealand in 1992, and marketed under the 1), the A. deliciosa Hayward cultivar is the most popular variety commercial name ZESPRITM GOLD Kiwifruit -ZESPRITM is the marketed commercially.13 name of the marketing subsidiary of Kiwifruit New Zealand, the Hayward (female) variety successor to the New Zealand Kiwifruit Marketing Board.18 The fruit is of average size and very characteristic for having a very pronounced This variety presents medium vigorous plant and is very productive. floral end (Figure 4). It has yellow pulp and high in sugar, vitamin C, The flowers are usually solitary, one per peduncle, large, 5 to 7cm in E and iron, with a tropical fruit flavor. Very productive and harvest diameter and very attractive, with white petals (Figure 3). The fruit season similar to Hayward.13 is large, with an average weight greater than 100g, ellipsoidal shape, and has a high density, which makes it one of the best in the volume- weight ratio of all the cultivated Actinidia species. The skin is brown, with a background more or less green, and is coated with a thin and thin hair (Figure 3). Figure 4 A. chinensis Hort16A kiwi fruit.18 Actinidia arguta and Actinidia kolomikta cultivars (baby kiwi) Two other Actinidia species have a fruit of obvious commercial Figure 3 A. deliciosa Hayward kiwi fruit (A) and flower (B). potential: these are A. arguta and A. kolomikta.19 The fruits of these species are known globally as “baby kiwi”, “mini kiwi “or” kiwi The pulp is very juicy at maturity and with very good flavor, bright berry13 because the fruit is about the size of a European gooseberry or green, turning yellowish in the maturity of consumption. It also well grape, rarely exceed 25g. The skin is smooth and polished, completely adapted to conservation by refrigeration, up to more than six months in hairless, without any villus and edible, colored green and with reddish an atmosphere controlled. In the last years some clones have appeared tones in some varieties. The pulp is green bright, with the flavor similar derived from Hayward, with better characteristics of the fruit.13,15,16 to green kiwi, but sweeter. They have a greater content in antioxidants Other varieties of traditional green kiwi are present in Table 1. that the rest of the kiwis, and a higher vitamin content and minerals. According to Garcia et al.,13 Allison, Elmwood, Green sil, Gracie, The conservation period is short conservation, about 2 or 3months”.13 Vicent, Blake, etc. are cultivars similar to these, but all of them have The cultivars of this two species are presented in Table 1. no commercial interest because of the smaller caliber of the fruit, Citation: Pinto T, Vilela A. Kiwifruit, a botany, chemical and sensory approach a review. Adv Plants Agric Res. 2018;8(6):383‒390. DOI: 10.15406/apar.2018.08.00355 Copyright: Kiwifruit, a botany, chemical and sensory approach a review ©2018 Pinto et al. 385 Table 1 Kiwi cultivars Species Cultivars References Is a clone derived from Hayward, very productive, which has an average weight 20% higher than this and matures a week before? It produces a Hayward CLON 8 13 lower percentage of double fruits and is more resistant to frost. It is also less susceptible to Phytophthora that Hayward Is a mutation of Hayward' very productive, with good size fruit and lacks Top Star 13 hairiness.