Forget chip fat, sugar cane or rapeseed oil – the latest source of biofuel could be watermelons.

    Scientists have discovered that the fruit is a great source of sugar that can be readily distilled into alcohol to power cars and farm machinery.

    And because retailers rejects 360,000 tons of "substandard" fruit annually in America alone they could be used as an economical way to make fuel.

    The waste from US growers could produce nearly two million gallons （nine million litres） of biofuel per year.

    In the study, researchers at the United States Department of Agriculture set out to determine the biofuel potential of juice from 'cull' watermelons – those not sold due to cosmetic imperfections, and currently ploughed back into the field.

    About a fifth of each annual watermelon crop is left in the field because of surface blemishes or because they are misshapen.

    Dr Wayne Fish, who led the team, found that 50 per cent of the fruit was fermentable into ethanol which could provide valuable fuel.

    "We've shown that the juice of these melons is a source of readily fermentable sugars, representing a heretofore untapped feedstock for ethanol biofuel production," he said.

    The study, published in the journal Biotechnology for Biofuels, discovered that watermelons could produce around 20 gallons of fuel per acre from fruit that otherwise would go to waste.

    Production of biofuels has been targeted by western governments as a way to bolster renewable energy targets.

    The European Union has a target for 2010 that 5.75 per cent of transport fuels should come from biological sources, but the target is unlikely to be met.

    The British government's Renewable Transport Fuel Obligation requires five per cent of the fuel sold at the pump by 2010 to be biofuel.

    不用再考慮剩油、甘蔗和菜籽油了--西瓜可成為生物燃料的一個(gè)最新來源。

    科學(xué)家發(fā)現(xiàn)，西瓜中含有大量糖份，糖可直接用于提煉酒精，從而為汽車和農(nóng)用機(jī)械提供動(dòng)力。

    每年僅美國的零售商遺棄的"不合格"水果就達(dá)36萬噸，而這些水果可通過一種十分經(jīng)濟(jì)的方法來制造酒精。

    美國水果種植商每年扔掉的水果可生產(chǎn)出近200萬加侖（900萬公升）的生物燃料。

    在這項(xiàng)研究中，美國農(nóng)業(yè)部的研究人員開始測(cè)定這些"被淘汰"西瓜的汁液究竟具有多大的潛在利用價(jià)值。被淘汰西瓜指的是那些由于外表瑕疵未上市，又被淘汰回地里的西瓜。

    每年約有五分之一的西瓜因外表瑕疵或形狀不規(guī)則而被丟棄。

    研究小組負(fù)責(zé)人韋恩？費(fèi)什發(fā)現(xiàn)，50%的西瓜可發(fā)酵產(chǎn)生乙醇這種寶貴的燃料。

    他說："我們發(fā)現(xiàn)西瓜汁中含有易發(fā)酵糖，這種原料在乙醇生物燃料的生產(chǎn)中尚未被利用過。"

    這項(xiàng)在《生物燃料的生物科技》期刊上發(fā)表的研究發(fā)現(xiàn)，每英畝的西瓜能產(chǎn)生約20加侖的燃料，而（如果不加以利用，）這些水果就會(huì)被白白浪費(fèi)。

    西方國家瞄準(zhǔn)制造生物燃料，以此促進(jìn)可再生能源的發(fā)展。

    歐盟計(jì)劃到2010年實(shí)現(xiàn)"5.75%的交通燃料源于生物燃料"的目標(biāo)，但似乎很難實(shí)現(xiàn)。

    英國政府的《可再生交通燃料義務(wù)法》規(guī)定，到2010年，生物燃料占加油站所售燃料的比例應(yīng)達(dá)到5%.