日韩欧美耩品综合久久-日韩欧美激情网站-日韩欧美激情国产一区二区蜜-日韩欧美激情91-日韩欧美黄色影片-日韩欧美黄色激情片

近日，澳大利亞CSIRO高級研究員Nick博士和上海海洋大學吳旭干教授收到“International Aquafeed”雜志社的邀請，就“雨生紅球藻蝦青素在鮭鱒魚上的應用研究進展”向水產飼料界做一個概述性介紹。

今天，我們帶著大家一起去看一看。

Algal carotenoids as pigments for salmonids.

藻類類胡蘿卜素作為鮭魚的色素。

Dr Nick Wade - Senior Research Scientist, CSIRO Agriculture and Food, Australia; and Dr Xugan Wu – Director of Department of Aquaculture Nutrition and Feed, Shanghai Ocean University, China （Nick Wade博士——澳大利亞CSIRO農業和食品高級研究科學家；中國上海海洋大學水產營養與飼料系主任吳旭干博士）

Carotenoids provide the intense red colouration of salmonid muscle through the dietary inclusion of the synthetic pigment astaxanthin (Axn). In aquaculture, synthetically derived Axn is the predominant source included in aquafeeds due to the lower cost of production. Alternative sources of carotenoids from bacteria, yeast or algae have been under development for decades but have not been widely adopted, largely due to increased cost. As natural antioxidants, carotenoids neutralise free radicals and in humans have been shown to prevent or slow down chronic diseases, cellular damage and aging. Specifically, they are known to reduce the risk of inflammation, heart disease, and cancer, type 2 diabetes, chronic eye and macular diseases, obesity, and neurodegenerative disorders (Sathasivam et al 2018).

中譯：通過在飲食中添加合成色素蝦青素(Axn)，類胡蘿卜素可使鮭魚肌呈現強烈的紅色。在水產養殖中，由于生產成本較低，合成蝦青素是添加的主要來源。幾十年來，人們一直在開發從細菌、酵母或藻類中提取類胡蘿卜素的替代來源，但一直沒有被廣泛采用，這主要是由于成本較高。作為天然的抗氧化劑，類胡蘿卜素可中和自由基，預防或減緩人體慢性病，細胞損傷和衰老。具體來說，可以降低炎癥、心臟病、癌癥、2型糖尿病、慢性眼睛和黃斑疾病、肥胖和神經退行性疾病的風險(Sathasivam等人，2018年)。

Scalable and cost effective production of algal carotenoids

海藻類胡蘿卜素的規模化生產和成本效益

Considerable progress has been made in the production of carotenoids from algae, encompassing multiple algal species and carotenoid compounds (Ambati et al 2019). The freshwater microalga Hematoccocus pluvialis shows great potential as a source of natural pure Axn. It can be grown from pure flask cultures to vast expanses of enclosed photobioreactors (Figure 1) for use in the nutraceutical, cosmetic, and food industries. Through years of culture innovation, Yunnan Alphy has been able to produce up to 160 tonnes of algal biomass annually at an Axn content of 3-5%.

After optimising and expanding algal biomass during the green growth phase, stressful conditions such as strong sunlight, water chemistry and temperature, cause the algae to produce Axn as a way for the cell to protect itself against the “tough” environment. This causes the algae to change from green to red. The Axn accumulation period is around 15 to 22 days depending on the season with production conducted throughout the year. The product holds many production and safe food certifications such as organic and EU novel foods. Such scale of production and Axn content now makes algal carotenoids a realistic alternative for aquaculture.

中譯：藻類類胡蘿卜素量產已經取得了相當大的進展，包括多種藻類物種和類胡蘿卜素化合物(Ambati等，2019年)。淡水微藻雨生紅球藻是天然純蝦青素的優質提取物。它可以從純燒瓶培養，到光密閉生物反應器累積(圖1)，主要用于營養，化妝品和食品工業。通過多年的培養創新，云南愛爾發每年能夠生產高達160噸的藻粉，蝦青素含量為3-5%。

在綠色生長階段優化和擴大藻類生物量后，強烈的陽光、水化學和溫度等壓力條件導致藻類產生蝦青素，這是細胞以此保護自己免受“艱苦”環境的一種方式。這導致藻類從綠色變成紅色。根據季節的不同，蝦青素積累時間約為15 - 22天，全年不間斷生產。該產品擁有許多生產和安全食品認證，如有機認證和歐盟新資源食品。這樣的生產規模和蝦青素含量使得藻類類胡蘿卜素應用于水產養殖成為可能選擇。

Figure 1 – H. pluvialis production facility in southern China (Photo: Yunnan Alphy Biotech Pty Ltd) 中國南部雨生紅球藻生產基地（圖片來源:云南愛爾發生物科技有限公司）

Comparison of pigment sources in trout

鱒魚色素來源的比較

In a recent trial (Wang et al, unpublished) under commercial conditions, rainbow trout were grown from 0.6 kg to over 2 kg on diets that contained 30 mg/kg Axn from different sources: Synthetic Axn (Carophyll Pink); Yeast Axn – Phaffia rhodozyma; Algal Axn – H. pluvialis; No Axn – no additional supplementation. Results showed that Axn source did not affect weight gain, somatic indices or flesh pigmentation, demonstrating that each carotenoid source had no effect on production performance or product quality.

However, the liver of fish fed algal carotenoids had significantly increased total antioxidant capacity, while total lipid content was significantly increased in the muscle. These results suggest that there could be additional benefit of algal Axn during periods of increased environmental stress. All carotenoid sources represent viable commercial options for producing healthy fish with high quality fillet attributes.

中譯：在最近的一項商業條件下試驗中(Wang 等，未發表)，虹鱒魚從0.6公斤長到超過2公斤，飼料中含有30毫克/公斤來自不同來源的蝦青素：人工合成蝦青素；紅法夫酵母蝦青素；雨生紅球藻蝦青素；未添加蝦青素的對照組。結果表明，不同蝦青素不會影響增重、軀體指數和色素沉積，因此不會影響養殖性能和品質。

但是，飼喂紅球藻蝦青素組魚體肝臟的總抗氧化能力顯著提高，肌肉中的總脂含量顯著增加。這些結果表明，在養殖環境壓力存在時（如：高溫等），紅球藻蝦青素能夠提高魚類的養殖效果，如：提高攝食量和抗氧化能力。魚類養殖企業可以根據自身需求，選擇合適的類胡蘿卜素來源進行品質調控。

Figure 2 – Pigmentation of trout muscle with different Axn sources (Photo: Lei Wang, Shanghai Ocean University) 圖2 -不同蝦青素來源的鱒魚肌肉色素沉著(圖片來源：上海海洋大學王磊)

Improved digestibility of algal carotenoids in Atlantic salmon

提高大西洋鮭魚藻類類胡蘿卜素的消化率

Typically included at 50-60 ppm, dietary Axn can account for up to 25% of the cost of diet. However, overall retention in the muscle often less than 10%. The digestion, absorption and deposition of Axn is affected by factors including Axn source, dietary inclusion level and the ingredient composition of the diets. Axn from algae is esterified, a natural modification where a fatty acid is attached to one or both ends of the carotenoid molecule, which can also impact digestion. In a study on Atlantic salmon (Courtot et al 2022), apparent digestibility (AD) of algal Axn was shown to be significantly higher than synthetic Axn.

Furthermore, the AD of Axn was shown to be enhanced by the dietary inclusion of canola oil rather than poultry oil or tallow (Figure 3). These oils differ markedly in their fatty acid composition, with canola oil enriched with mono-unsaturated fatty acids (MUFA), while tallow was enriched with saturated fatty acids (SFA). This led to the finding that Axn digestibility was significantly positively correlated with dietary MUFA content, especially 18:1n-9cis as one of the main fatty acids in canola oil. This result provides evidence that the type and composition of oil provides significant improvement of algal Axn digestibility, which is expected to lead to improved utilisation and muscle retention.

In summary, the inclusion of algal biomass as a source of natural Axn combined with the inclusion of MUFA rich oils such as canola can lead to significant improvements in the utilisation of dietary Axn, and therefore the more cost-effective production of high-quality Atlantic salmon.

中譯：三文魚飼料中通常添加50- 60ppm的蝦青素，蝦青素最高可占飼料成本的25%。但是，三文魚肌肉對飼料中的蝦青素保留率通常低于10%。蝦青素的消化、吸收和沉積受多種因素影響，包括蝦青素來源，添加水平和飼料組分。紅球藻蝦青素是酯化的，脂肪酸結合在游離類胡蘿卜素分子的一端或兩端，這種變化也會影響水產動物對蝦青素的消化和吸收。課題組最近對大西洋鮭魚的研究表明：三文魚對紅球藻蝦青素的表觀消化率(AD)明顯高于合成蝦青素(Courtot et al 2022)。

此外，飼料中添加菜籽油比禽油或牛油更會增強蝦青素的表觀消化率(圖3)。這些油脂的脂肪酸組成存在顯著差異，菜籽油富含單不飽和脂肪酸(MUFA)，而牛油富含飽和脂肪酸(SFA)。由此可見，蝦青素消化率與飼料中MUFA的含量呈顯著正相關，特別是18 - 1n-9的含量。這個研究結果證明油脂種類及脂肪酸組成會顯著影響魚類對紅球藻蝦青素的消化率。

綜上所述，添加紅球藻來源的天然蝦青素，結合添加富含MUFA的菜籽油，可以顯著提高飼料中蝦青素的利用率，從而降低飼料成本，生產出更高性價比的高質量大西洋鮭魚。

Figure 3 Apparent digestibility (AD% digested) of carotenoids for the four experimental diets and positive correlation of carotenoid AD with dietary mono-unsaturated fatty acid (MUFA) levels (adapted from Courtot et al 2022).圖3 四種試驗飼糧中類胡蘿卜素的表觀消化率(AD%消化率)以及類胡蘿卜素表觀消化率與飼糧中單不飽和脂肪酸(MUFA)水平的正相關關系(適配自Courtot等人，2022年)。

References

Ambati, R. R., D. Gogisetty, R. G. Aswathanarayana, S. Ravi, P. N. Bikkina, B. Lei and Y. P. Su (2019). Industrial potential of carotenoid pigments from microalgae: Current trends and future prospects. Critical Reviews in Food Science and Nutrition 59(12): 1880-1902.

Courtot, E., D. Musson, C. Stratford, D. Blyth, N. A. Bourne, A. N. Rombenso, C. J. Simon, X. G. Wu and N. M. Wade (2022). Dietary fatty acid composition affects the apparent digestibility of algal carotenoids in diets for Atlantic salmon, Salmo salar. Aquaculture Research 53(6): 2343-2353.

Sathasivam, R., & Ki, J. S. (2018). A review of the biological activities of microalgal carotenoids and their potential use in healthcare and cosmetic industries. Marine drugs, 16(1), 26.

Wang L, Long X, Sun W, Li Y, Wang X, Zhang Y and Wu X (2022). Effects of three different sources of dietary Axn on the growth performance, coloration, and antioxidant capacity of rainbow trout Oncorhynchus mykiss. under review

作者：Nick博士&吳旭干教授，特別鳴謝