## 1 Introduction  
Genova (_Ocimum basilicum_ cv. 'Genovese'), a cultivar of sweet basil (_Ocimum basilicum_ Linn.), is a member of the Perilla family, commonly known as common basil [1]. Sweet basil is a perennial herb from the Lamiaceae family produced primarily in the regions of Genova, Imperia, and Savona in Liguria, Italy [2]. Sweet basil is used in both Ayurvedic and Unani medicine as a medicinal herb [3] and possesses antibacterial properties as well as inhibitory properties against HIV-1 reverse transcriptase and platelet aggregation [1, 4, 5, 6]. Furthermore, aromatic compounds extracted from sweet basil are used in cosmetics and natural fragrances [3] and drunk as basil tea [1]. Genova is popular for its use in pasta sauces [7] and contains high levels of polyphenol components, such as rosmarinic acid, a caffe acid derivative, chicoric acid, and caffe acid, with particularly high rosmarinic acid content [8, 9]. Rosmarinic acid exhibits antioxidant, anti-inflammatory, and neuroprotective properties [9] and is abundant in sweet basil and other plants of the Lamiaceae family, such as egoma and lemon balm [10, 11]. Genova contains high levels of aromatic phenyl-propanoids, sesquiterpenes, and monoterpenes [12]. Although Genova has the highest antioxidant potential of any sweet basil [9, 13], only a few studies have been conducted on processing methods that retain its antioxidant properties. For example, there exist studies on the effects of different drying methods (microwave, sun-drying at 12.2-21.0 \({}^{\circ}\)C and 37-98% humidity, and machine-drying (MD) at 45, 50, or 55 \({}^{\circ}\)C) on ascorbic acid, phenol, and chlorophyll contents and antioxidant activity [14]; and optimization of osmotic dehydration to improve dried product quality and to limit changes in appearance, texture, flavor, and color [15]. We have previously examined the tea-making process of _Ocimum gratissimum_ with respect to the steaming duration (1 or 2 min), drying method (freeze-drying (FD), MD, or shade-drying (SD)), drying temperature (40 or 80 \({}^{\circ}\)C), roasting (with or without), and fermentation treatment (with or without); however, detailed studies on its steaming duration and drying temperature were not available due to a lack of processing conditions [16]. If a method is established to retain more efficiently the antioxidant activity, functional components, and aroma compounds of raw materials, highly functional tea will be developed and used in cosmetics, natural fragrances, and the pharmaceutical industry. It has also been postulated that the use of Genova will expand.  
Therefore, the objective of this study is to develop a strategy to process Genova for high functionality. Specifically, we determined detailed conditions for the steaming duration and drying temperature, which have not been previously reported, and elucidated the effects of tea processing on the antioxidant components and properties of Genova tea. Moreover, the color and aroma components, which are important indicators of tea quality, were also evaluated. Scanning electron microscopy (SEM) was used to verify the effects of tea processing on leaf tissue structure and, ultimately, antioxidant properties and quality.