雅思阅读Unit3VIP免费

EnhancingtheTasteofOurFoodAWhatareyourfavoritefoods?Doyoulikepizza,hamburgers,roastpork,orsweetcakesandcookies?Chancesarethat,whateveryoulikebest,ithasastrongtasteandasalty,sweetorsavoury[´seivəri]（辣）flavour[´fleivə]（滋味).Peoplegenerallyliketoeattastyfoods,andthiscancreatepotential（潜在的）healthproblems,especiallywiththeconsumption[kən´sʌmpʃən]（消费）offastorprocessed（加工的）food.Fastfoodtraditionallycontainalotofsaltorsugar,becausethisisacheapwaytomakefoodtastegoodanditencouragespeopletobuymorecookies,chipsandsoftdrinks,forexample.However,peoplearebecomingincreasingly（越来越多的）awareofthedangersofanunhealthydiet,andthemanufacturers[,mænjuˊfæktʃərəz]（厂商）ofprocessedfoodknowthatsaleswillincreaseiftheycanadvertisethattheirproductshavelesssaltorsugar.Theyalsoknowthatiftheirproducttastesbland(乏味的)orboring,noamountofhealthbenefitswillmakeitapopularchoicewithconsumers,andtheywilllosemoneyiftheirproductisnotpopular.However,anewtechnologyiscurrentlybeingdevelopedthatmayallowfastfoodmanufacturerstoreducesaltandsugarwithoutsacrificing(影响)taste.BIfyoustickout(伸出)yourtongueandlookinthemirror,youwillseethatitiscoveredwithtinybumps[bʌmp]（凸起物）.Thesebumpsarecalledtastebuds(味蕾)andtheyarethereceptorsinourskinthatallowustotastedifferentkindsoffoods.Therearefivedifferenttastereceptors,forsweet,salty,sour,bitterandsavoury(辣)flavours.Whenwearebornwehavealotoftheseonthefoodofourmouthaswellasonourtongue,butaswegetolder,welosetastebuds,whichiswhyolderpeoplefindithardertotastethings.Adultstypicallyhaveabout10,000tastebuds,butolderpeoplemayhaveasfewas5,000.Wehavemorereceptorsforbittertastesthanforanyothers;researchersthinkthatthismaybebecausethesetastebudswarnusiffoodispoisonous[´pɔizənəs](有毒的).CThefoodthatweeatcontainsnaturalchemicalsthatfitintothedifferentshapedreceptorsonourtongues;forexample,sweetfoodstrigger(引起)thesweetreceptors.Thetechnologytomimic(模仿),orcopy,thesenatureflavourswithchemicalssuchasaspartame[´æspa:teim](阿斯巴甜)hasbeeninexistenceforalongtime,andaspartameisacommoningredient(原料)inmanydietsoftdrinksandotherdietproducts.Whileaspartameallowsustoexperienceasweettastewithouteatingsugar,italsohasdisadvantages.Firstly,manypeopledonotlikeitsbitteraftertaste(余味),andsecondly,somepeoplesaythatitisbadforhealthiftakeninlargequantities.DHowever,anewtechnologyisbeingdevelopedthatmaybeanimprovementonartificial(人工的)sweetenersandotherchemicals.Tasteenhancers(增强剂)targetthetastereceptorsonourtongues,andtheymakeusmoresensitivetosweet,sourorsaltytastes.Justafewmolecules[´mɔlikju:ls](分子)ofatasteenhancercoulddoublethesweetnesseffectofateaspoonofsalt.Thismeansthatinsteadofusingartificialchemicalstomakefoodtasty,foodmanufacturerscouldusehalfthequantityoftherealsubstance(实物)andatinyquantityoftasteenhancertomakethefoodtastegood.Thishasthepotentialtosavefoodmanufacturersmoney,byreplacinglargequantitiesofsugarandsaltwithtinyamountsofchemicals.Itcouldalsobenefitourhealthifwecaneatfoodthattastesgoodandislowinsugarandsalt.ETasteenhancershaveotheradvantages,too.Peoplegenerallydonotlikebittertastingfood,butreversing[ri´vəs](完全改变)thistechnologysothatthebittertastereceptorsareblocked(阻塞的)insteadofstimulated[´stimjə,letid](受刺激的)mayreducethebittertasteofsomehealthyfoods.Thismeans,forexample,thatpeoplemaybepersuadedtoeatmoreso...