# Duality and Flavor of 'Aliza' Fruit: A Unique Pomelo \(\times\) Mandarin Hybrid
## 1 Introduction  
Citrus is the most important fruit tree crop in terms of cultivation and production values and is grown in the tropical and subtropical regions of the world, in more than 140 countries, with a total annual production of over 100 million tons [1, 2]. The most important commercial citrus species are sweet orange (_Citrus sinensis_), mandarin (_C. reticulata_), graprefruit (_C. paradisi_), pomelo (_C. maxima_), lemon (_C. limon_) and lime (_C. aurantifola_) [3]. Some commercial varieties are hybrids of different citrus species. For example, the 'Murcott' tangerine is a hybrid of orange and mandarin (_C. sinensis_\(\times\)_C. reticulata_), the 'Minnicola' tangerine is a hybrid of graprefruit and mandarin (_C. paradisi_\(\times\)_C. reticulata_) and 'Orbolanco' is a hybrid of graprefruit and pomelo (_C. paradisi_\(\times\)_C. grandis_) [4, 5].  
It is worth noting that pomelo (_C. maxima_), mandarin (_C. reticulata_) and citron (_C. media_) are considered to be the three true original citrus ancestors, from which all other citrus species have evolved [3, 6]. For example, sweet orange (_C. sinensis_) evolved from a hybridization between an early admixture mandarin and pomelo, and graprefruit (_C. paradisi_) evolved from a hybridization between pomelo and sweet orange [7, 8]. In the current study, we characterized the quality of the 'Aliza' fruit, which is a new and unique pomelo \(\times\) mandarin hybrid (_Citrus maxima_ cv. Red Chandler \(\times\)_Citrus reticulata_ cv. Ora) developed by theIsraeli citrus breeding program at the Volcani Institute. 'Aliza' is a new commercial variety currently grown in several countries, including Israel, Spain and South Africa.  
In a previous study, we demonstrated that the juice of 'Aliza' fruit differs in its sensory quality from orange and graprefruit juices [9]. In addition, 'Aliza' fruit contains low levels of funcoumarins responsible for the graprefruit-drug interaction phenomenon, also known as the graprefruit effect, which is caused by the inhibition of the CYP3A4 drug-metabolism enzyme. This means that 'Aliza' fruit have a nutritional advantage as they can also be consumed by people who cannot consume graprefruit due to particular medications they are taking [10; 11].  
The quality of citrus fruit is determined by a combination of various factors, including external appearance, biochemical composition and flavor. The external appearance of fruit is determined by several physical traits, such as size, shape and weight, peel thickness, ease of peeling, amount of seeds and peel and pulp color. The biochemical and nutritional composition of citrus fruits is determined by the amounts of total soluble solids (TSS), acids, vitamin C and carotenoids that they contain among other nutrients [12; 13]. The perceived flavor of citrus fruit is due to the combination of various taste, aroma and mouth-feel sensations. The taste of citrus fruit mainly results from sensations of sweetness, sourness and bitterness; the aroma of citrus fruit is due to the presence of dozens of aroma volatiles that belong to several chemical classes, including terpen, aldehydes, alcohols, esters and ketones; and mouthfeel sensation is mainly determined by the juiciness and/or dryness of the fruit segments [14; 15].  
In the present study, we analyzed the quality and flavor of 'Aliza' fruit, and compared it with other common commercial citrus fruits, particularly pomelo, graprefruit, orange and mandarin that ripen at the same period.