On food and cooking the science and lore of the kitchen ( PDFDrive ) 721

sweet oranges by a mixture of lycopene and
beta-carotene and by cryptoxanthin. The
purple-red of blood oranges comes from
anthocyanins.

Citrus anatomy. The protective outer rind
includes aromatic oil glands embedded in a
bitterwhitepith,thealbedo.Eachsegment,or
carpel,of a citrus fruit consists of many
delicate juice sacs contained within a strong
membrane.
Thetasteofcitrusfruitsiscreatedbya
handfulofsubstances,includingcitricacid
(sonamedbecauseitistypicalofthefamily),
sugars,andcertainbitterphenoliccompounds,
whichareusuallyconcentratedinthealbedo
andpeel.Citrusfruitsaresurprisinglyrichin
thesavoryaminoacidglutamate,sometimes


rivalingthetomato(orangesreach70
milligramsper100grams,grapefruits250).
Theycontainlittlestarchandthereforedon’t
sweetenmuchafterpicking.Usuallythe
blossomendofthefruitcontainsbothmore
acidandmoresugars,andsohasamore
intensetastethanthestemend.Neighboring
segmentscanalsovarysignificantlyintaste.
Citrusaromaisproducedbothbytheoil
glandsintheskinandoildropletsinthejuice
vesicles—andthesetwosourcesareusually

quitedistinct.Generallythevesicleoils
containmorefruityesters,andpeeloilmore
greenaldehydesandcitrusy/spicyterpenes(p.
274).Afewaromacompoundsaresharedby
mostcitrusfruit,includinggenericallycitrusy
limoneneandsmallamountsofeggy
hydrogensulfide.Infreshlymadejuice,the
sacoildropletsgraduallyaggregatewiththe
pulpymaterials,andthisaggregationreduces
thearomaavailabletothetaster,especiallyif
someofthepulpisstrainedoff.