On food and cooking the science and lore of the kitchen ( PDFDrive ) 726

autumnandwinter.Thepigmentstendto
accumulateattheblossomendandinvesicles
immediatelynexttothesegmentwalls,and
continuetoaccumulateafterharvestwhenthe
fruitsareheldincoldstorage.Thepigments
andtheirphenolicprecursorsgiveblood
orangesahigherantioxidantvaluethanother
oranges.Theuniqueflavorofbloodoranges
combinescitrusnoteswithadistinct
raspberry-likearoma.
Acidlessorangesaregrowninsmall
numbersinnorthAfrica,Europe,andSouth
America,andhaveaboutatenththeacidity—
andlessorangearoma—ofcommonand
naveloranges.
Sourorangescomefromadifferent
speciesthanthekindsdescribedabove,and
arebothsourandbitter(thanksnottolimonin
butarelatedcompound,neohesperidin),with
anintenseanddistinctivepeelaroma.They
arrivedinSpainandPortugalinthe12th
century,andsoondisplacedquinceasthe


mainingredientinmarmalade.Sour-orange
flowersareusedtomakeorangeflowerwater.
Grapefruit The grapefruit originated as a
hybrid of the sweet orange and pummelo in
theCaribbeaninthe18thcentury,andisstill
mainlygrownintheAmericas.Theredtypes
owetheircolortolycopene,andfirstappeared

as chance mutations in Florida and in Texas
earlyinthe20thcentury(themorerecentand
popularStarRubyandRioRedvarietieswere
created by intentionally inducing mutations
with radiation). Unlike the anthocyanin
coloration of blood oranges, grapefruit
lycopene requires consistent high growing
temperatures to develop well, appears evenly
throughallthejuicevesicles,andisstableto
heat.Thecharacteristicmoderatebitternessis
caused by a phenolic substance called
naringin, whose concentration declines as the
fruit ripens. Like navel oranges, grapefruits
also contain a precursor of limonin, and its