HORTSCIENCE 52(4):488–497. 2017. doi: 10.21273/HORTSCI11570-16 Camellia as an Oilseed Crop Haiying Liang1 Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29634 Bing-Qing Hao, Guo-Chen Chen, Hang Ye, and Jinlin Ma1 Guangxi Forestry Research Institute, Guangxi Key Laboratory of Non-wood Cash Crops Cultivation and Utilization, Nanning, P.R. China, 530002 Additional index words. biodiesel, cultivar, edible oil, new horticultural crop, oil camellias Abstract. Camellia is one of the four main oil-bearing trees along with olive, palm, and coconut in the world. Known as ‘‘Eastern Olive Oil,’’ camellia oil shares similar chemical composition with olive oil, with high amounts of oleic acid and linoleic acid and low saturated fats. Camellia was first exploited for edible oil in China more than 1000 years ago. Today, its oil serves as the main cooking oil in China’s southern provinces. Introduction of camellia oil into the Western countries was delayed until the recognition of its many health benefits. Although popularity for the oil has yet to grow outside of China, interest has emerged in commercial production of camellia oil in other countries in recent years. Unlike seed-oil plants that are grown on arable land, oil camellias normally grow on mountain slopes. This allows the new crop to take full usage of the marginal lands. To facilitate promoting this valuable crop as an alternative oil source and selecting promising cultivars for targeted habitats, this paper reviews the resources of oil camellias developed in China, use of by-products from oil-refining process, as well as the progress of developing camellias for oil production in China and other nations. The genus Camellia comprises a group of (Marshall Islands Press Release, 2013; Rolfe, seeds of traditional camellia varieties can about 100 species native to a number of areas 1992; http://www.stampnews.com/stamps/ range between 24% and 50% with an average throughout China, southeast Asia, and Japan stamps_2013/stamp_1357919298_398033. of 30% (Huang et al., 2013). Some of the (Min and Bartholomew, 2007; Ming, 2000). html; http://www.wnsstamps.post/en/stamps/ new Camellia oleifera cultivars can reach They are evergreen flowering trees or shrubs AU007.03). 53% oil per dry seed (Yang et al., 2016). with broad, shiny, dark green leaves, and In contrast to its worldwide contributions Camellia oil has a relatively high smoke point have primarily a subtropical and warm- as an ornamental plant and as a tea producer, when compared with commercial oils such as temperate distribution. Among them, Camel- camellia oil is less known to the world despite olive oil, at a range of 210–252 °C (Allen, lia sinensis and Camellia japonica are the it has long been important in China, as well as 2015; Miao et al., 2013; Zheng et al., 2011), best internationally known and cultivated in Japan, however, to a lesser extent. Camel- which makes it suitable for deep frying, stir species, for tea production and ornamental lia is one of the four main oil-bearing trees frying, and as a salad dressing. The nutri- value, respectively. These two species made along with olive, palm, and coconut in the tional value of camellia oil is well docu- their way to the Western world in the 18th world (Robards et al., 2009). Oil from ca- mented. The unsaturated fatty acid content in century after being cultivated and treasured mellia seeds is also known as ‘‘Eastern Olive camellia oil complies completely with the in the Orient for thousands of years (Cothran, Oil,’’ because it shares similar chemical international nutritional standards of ‘‘omega 2004). Currently, there are more than 22,000 composition with olive oil, with high meals,’’ and can reach as much as 90% camellia varieties or cultivars cataloged in amounts of oleic acid and linoleic acid, and (80% oleic acid, 10% linoleic acid, and the International Camellia Society (http:// low saturated fats. Camellia was first linolenic acid) (Mondal, 2013), which may www.camellia-international.org/). In the exploited for edible oil in China more than be the highest amount so far reported in United States, there are more than 2300 1000 years ago (Shanan and Ying, 1982). edible oil (Feas et al., 2013). Its monounsat- cultivars registered with the American Camel- Today, camellia oil serves as the main cook- urated fatty acid and vitamin E contents are lia Society (https://www.americancamellias. ing oil in China’s southern provinces (Fig. 1), greater than that of olive oil. In addition, com/). Spain produces about 2.5 million especially in Hunan Province (Ruter, 2002), camellia oil contains other functional com- camellia plants annually, mostly C. japonica, and more than 90% of global camellia oil ponents such as saponins, polyphenol, and which are exported throughout Europe as production is from China (Zhao et al., 2015). squalene. Its beneficial effects have been re- ornamentals (Salinero et al., 2012). Because Depending on the species, cultivar, and cently reviewed and summarized in Li et al. of its popularity, many countries and regions, environmental conditions, oil content in (2011), which include antitumor, reducing including China, Japan, Korea, Vietnam, Belgium, Haiti, Rwanda, the United States, Albania, France, New Zealand, Poland, Aus- tralia, Spain, the Marshall Islands, and the island of Jersey, have issued postage stamps honoring the importance of the camellia Received for publication 10 Nov. 2016. Accepted for publication 25 Jan. 2017. We would like to acknowledge the support from the Distinguished Expert Special Fund for the award, Physiology of Flowering of Major Cash Non-wood Crop Species in Guangxi Zhuang Au- tonomous Region, P.R. China, and Clemson Uni- versity, Clemson, SC. We also thank Yun Li from Beijing Forestry University, China, for her assis- tance with Figure 3. 1Corresponding authors. E-mail: hliang@clemson. edu or [email protected]. Fig. 1. Examples of edible camellia oil. 488 HORTSCIENCE VOL. 52(4) APRIL 2017 FEATURE blood lipid, protecting liver and heart, antisepsis, anti-inflammation, coronary heart disease prevention, delaying atheroscle- rosis, antioxidation, and immune function regulation. Thus, camellia oil has also long resistance been used in the production of traditional Relative disease (1–6, low to high) Chinese medicines, cosmetics, soaps, and hair oil. With growing recognition of its nutri- tional value, there is a growing demand for index Refractive camellia oil. The cultivation acreage in China is expected to reach 6.5 million hectares with an annual camellia oil pro- duction of 2.5 million tons by 2020 (China value Forestry Bureau, 2009). Interest has also (mg KOH/g) emerged in the commercial production of Saponification camellia oil in Western nations, such as the United States and Australia (Robards Oil property /100 g) et al., 2009; Ruter, 2002, 2011). The Food 2 and Agriculture Organization of the (g I Iodine value United Nations has recommended camel- lia oil as a high-quality, healthy vegetable oil (Ahmed and Wang, 2015). This paper reviews the resources of oil camellias Acid value developed in China, by-products from (mg KOH/g) oil-refining process, as well as the prog- ress of developing camellia for oil pro- duction in China and other countries. (w/w, %) Oil content Major Oil Camellia Species and in dry seeds Resources in China Seeds of all camellia species contain in dry kernel oil (Robards et al., 2009). However, oil (w/w, %) Oil content content and quality may vary with species. ) In China, the species being cultivated for –2 m oil production include C. oleifera Abel, C. · –1 meiocarpa Hu, C vietnamensis Huang, C. ha · chekiangoleosa Hu, C. yuhsienensis Hu, Oil yield (kg C. semiserrata Chi, C. reticulata Lindl, C. polyodonta How ex Hu, C. gigantocarpa Hu, C. octopetala Hu, C. semiserrata var. albiflora Hu et Huang, C. phellocapsa Kernel from dry Chang et Lee, C. pitardii Coh Stuart, C. produced crassissima Chang et Shi, C. nanyongensis seeds (w/w, %) Hu, C. subintegra Huang, C. rhytidocarpa Chang et Liang, C. weiningensis Y. K. Li, C. z chrysantha Hu Tuyama, C. brevituba Chang et Zeng, C. lutca Chang, C. taishunensis Hu, Seeds produced and C. osmantha. from fresh Camellia oleifera is the earliest species fruits (w/w, %) exploited for edible oil and accounts for 98% of the cultivated area in China, followed by C. meiocarpa (Yao et al., Peak Seed production Oil production 2005). Camellia osmantha is a new prom- production period (yr) ising species recently discovered by our group at Guangxi Academy of Forestry, China (Ma et al., 2016). Our preliminary Peak age (yr) studies (Wang et al., 2014) suggest that C. production osmantha trees grow fast and can tolerate drought, flooding, and high temperatures. 8–12 15 20–30 34–45 58.12–66.61 105–150 63.5–71.98 22–28 5.65 81.16 182.54 — 3 7–8 12–14 20–30 38–46 48–60 150 54–64.7 24–31.5 2.1 84.29 191.73 1.4693 3 9–10 15 50–60 12–20 45–56.8 150 28–48.5 20.30 80–86 496–496.9 1.4691 1.4691 4 7–8 10–12 30–40 12–20 45–56 150–225 37–48 — 1.0 8239 199.2 — 4 8–10 14–15 50–60 12–18 48–57 195 36–44 19–29.54 2.5 80 189 1.4667 6 9–10 12–15 40–50 12–20 56–68 225–255 50–56 21–28 2–4 81 195 1.4679 5 8–10 14–16 30–40 15–25 45–56 150–225 54.25–58.94 25–32 0.70 83.70 191.8 1.4687 4 3–49–10 7–9 15–18 25–30 50–60 12–15 >65 45–56 68–74 225–300 225–375 56.15–64.19 37.06–52.19 20.5–29.4 20.5–26.4 1.2 1.2 85.89 85.89 191.50 191.50 1.4690 1.4690 4 4 7–8 10–13 30–40 20–30 48–68 150–225 50.4–56.6 27–34.1 1–2 — — — 3 7–8 12–15 40–50 18–30.5 54–60 >225 37.96–46.78 21–30.61 0.24–1.70 75–88 194.5–200 1.4669 1 5–6 8–10 30–40 30–40 66–70 225–375 34.02–46.52 20.5–31.6 — 76–90 195.4–197.0 1.4683 3 Their flowers and fruits are abundant, with 4–5 8–10 30–40 25–30 65–75 225–375 41.73–56.20 21.47–33.73 0.8–1.2 91.4 205 1.4717 2 10–12 15 20–30 34–45 54–65 105–150 52 — 2.84 83.4 185.58 — — to bear an average of 2.65-kg fresh fruit per fruits (yr) square meter tree crown of a 5-year-old Age starting seedling.