On food and cooking the science and lore of the kitchen ( PDFDrive ) 720

andthesemayhavebeentheiroriginal
attraction,wellbeforehumanselection
developedvarietieswithsweetjuices.The
improvedvarietiesdohavearefreshing,tart
tosweet-tartjuicethatcanbeextractedwith
littlepulp.Thepeelisrichingel-making
pectins.Andcitrusfruitsarealsofairly
robust.They’renonclimacteric,sotheyretain
theirqualityforsometimeafterharvest,and
themeatypeeloffersgoodprotectionagainst
physicaldamageandattackbyspoilage
microbes.
Citrus Anatomy Each segment of a citrus
fruit is a compartment of the ovary, and is
stuffed with small, elongated bags called
vesicles, each of which contains many
individual microscopic juice cells that fill
with water and dissolved substances as the
fruitdevelops.Surroundingthesegmentsisa
thick, white, spongy layer called thealbedo,
usually rich in both bitter substances and in


pectin.Andridingatopthealbedoistheskin,
a thin, pigmented layer with tiny spherical
glands that create and store volatile oils.
Flexingapieceofcitruspeelwillbursttheoil
glands and send a visible, aromatic — and
flammable!—sprayintotheair.
Citrus Color and Flavor Citrus fruits owe
theiryellowandorangecolors(orangecomes

ultimately from the Sanskrit word for the
fruit) to a complex mixture of carotenoids,
only a small portion of which has vitaminA
activity.Thefruitpeelsstartoutgreen,andin
thetropicsoftenstaythatwayevenwhenthe
fruit ripens. In other regions, cold
temperatures
trigger
destruction
of
chlorophyll in the peel, and the carotenoids
becomevisible.Fruitsofcommerceareoften
picked green and treated with ethylene to
improvetheircolor,andcoatedwithanedible
wax to slow moisture loss. Pink and red
grapefruit are colored by lycopene, and red