PREPARATION AND HANDLING FRESH-CUT ROOT VEGETABLES MERETE EDELENBOS DEPT. OF FOOD SCIENCE AARHUS UNIVERSITY DENMARK merete.edelenos@food.u.dk
Preprtion nd hndling fresh-cut root vegetles Production Hndling nd Storge Processing nd Pckging Distriution nd Mrket Consumption Pre-hrvest Post-hrvest Processing Post-processing
CONTENT Chrcteristics of root vegetles The unit opertion Peeling nd cutting Wshing Pre-pckging tretments Pckging Reserch needs Conclusions
Root vegetles re mostly underground storge orgns contining soil Roots True tproots Includes swollen hypocotyl C Tuers Root vegetles
Root vegetles re iennil crops Root vegetles Seed Growth Termintion of root growth Dormncy Sprouting nd flowering Re-growth Seed Hrvest Nov Jn Mrch My Cold storge
ng/g fresh weight Root vegetles Chemicl constituents vry etween cultivrs 9000 8000 Totl terpene content in crrots 7000 6000 5000 4000 3000 2000 1000 0 Purple Hze Soprno Yellow Stone Nottinghm Torndo White Stin Mello Yello Niroi Neul Line 1 Bolero Genotype Adpted from Kreutzmnn et l. 2008
Sensory qulity vry etween cultivrs Tunus Rocket Root vegetles : f: t: Plo Chioggi Touchstone Golden Mikkelsen 2012
CHARACTERISTICS OF ROOT VEGETABLES Belong to mny different plnt fmilies Are iennil crops Continue to grow fter hrvest Cn e stored for up to 12 months Store minly sugrs Vry considerly in qulity depending on fmily, species, cultivr nd time of usge
Unit opertion The unit opertion for root vegetles Peeling Cutting ± Wshing Centrifugt. ±Pre-pckging tretment Pckging
Unit opertion An exmple with processing of crrot sticks Household Fctory A Fctory B Fctory C Bolero crrots Bolero crrots Bolero crrots Hnd peeling knife Trimming + rinsing Corse fine rsion peeling + rinsing Trimming Fine rsion peeling + rinsing Cool room overnight Cutting into 2 x 2 Cutting mm sticks Cold ir cooling on conveyer elt Centrifugtion Centrifugtion Cutting Wshing in tp wter Centrifugtion Household ox with ventiltion Pckging
Fctory A Fctory C Fctory A Fctory C Effect of processing Trimmed Peeled on visul qulity Trimmed 5 cm Unit opertion Trimming Peeling Cutting Fctory A Trimmed Trimmed Fctory A Fctory A Peeled Peeled Fctory C Fctory C Cut 5 cm 5 cm Frctures med Fctory A Fctory C Peeled Peeled Fctory C Cut Cut 5 cm 5 cm 5 mm ed Cut Cut 5 cm 5 cm 5 mm
Unit opertion Effect of processing on microil lod log CFU/g fter 1 dy in MAP t 5 o C 7 6 5 4 3 2 1 Fctory A Fctory B Fctory C 0 Coliforms Lctic cid cteri Yest & Mold
Unit opertion Effect of processing on sensory qulity Sensory scores from low to high 14 Household 12 Fctory A Fctory B Fctory C 10 8 6 4 2 c c 14 12 10 8 6 4 2 c 0 Ornge colour Wet surfce 0 Crrot flvour Sweetness Juiciness
Effect of processing on rom voltiles nd sensory qulity Voltile content (ng/g fresh weight) 1000 100 10 1 Control (cut) Cut Cut+spin Cut+wsh+spin pinene terpinolene cryophyllene Edelenos et l. (2010) Act Hort 876
Wshing to reduce totl microil lod Wshing 9 Microil lod (log CFU/g) 8 7 6 5 4 3 2 1 0 Control Pre-wsh wter Pre-wsh chlorine Pre-wsh ozone Wshed sticks chlorine 0 2 4 6 8 10 Totl sugrs Control/pre-wsh 6.3% Wshed sticks 5.2% Storge dys t 4 o C Adpted from Klier et l. 2004
Wshing to reduce microil lod Wshing B C A B C A
Phytochemicls in crrots Polycetylenes Phenolic cids Isocoumrins
Peeling Some phytochemicls re simply removed in the peeling process
Effect of processing on polycetylenes Prsnip discs
Effect of peeling on phenolic cids Peeling Crrot discs Knife hnd Fine rsion mchine Corse rsion mchine
White lush in root vegetles 5 cm
Pre-pckging Chitosn-sed coting to overcome white lush 6 mm crrot sticks
Gs composition (%) Pckging to mintin the initil sensory profile Pckging Juiciness (ns) Crrot odor (**) 5 4 3 2 1 0 Sour odor (***) Fermented/sour flvor** Crrot flvor (*) Sweetness (ns) Dy 0 8 dys in perf film 8 dys in non-perf film Storge time (dys) Edelenos et l. (2010) Act Hort 876
Pckging to prolong shelf-life Swede cues Pckging
Score from low to high.0 6.5 5 d 5 o C 7.0 10 d 10 o C 10.5 5 d 5 o C MA1 10 d 10 o C MA2 9 6.56.0 5 o C MA1 MA2-5% 8 10 o C MA2.0 A A MA1 MA2-5% A A B 7 B 6.0 MA2 A MA2-5% 6 B c B 5.5 A A A B A A A A A B B 5 5.5 c B B c B.5 A A A B 4 c c B 5.0 3.0 5.0 2 4.5 Swede Turnip Swede Turnip Swede Turnip 1.5 Dys Temperture Pckging Swede 4.5 Turnip Swede Turnip Swede Turnip 0 Swede Turnip Swede Turnip Swede Turnip Swede Turnip Swede Turnip Swede Turnip Dys Turnip Swede Turnip Dys Temperture Temperture Swede Turnip Pckging Pckging Dys Temperture Pckging s Totl sugrs (g/100 g FW) Sweetness fr low to high Pckging 7.0 Effect of time, temperture 5 d nd pckging on qulity Sugrs Totl sugrs (g/100 g FW) Temperture Pckging 10 d Sweetness Adpted from:
Score from low to high Totl sugrs (g/100 g FW) 7.0 6.5 6.0 5.5 5.0 4.5 Totl sugrs (g/100 g FW) 7.0 Whiteness 6.5 9 5 d 5 o C MA1 10 d 10 o C MA2 8 6.0 5 o C MA1 MA2-5% A A 7 10 o C MA2 A AB 6.0 A A MA2-5% A A MA1 B B 6 B B MA2 A A B MA2-5% c B 5.5 5 B A A A5.5 A B 4 c B B c A A c B 5.0 3 5.0 2 Score fr low to high Totl sugrs (g/100 g FW) 10 7.0 6.5 1 4.5 Swede Turnip Swede Turnip Swede Turnip 4.5 0 Swede TurnipDys Swede Turnip Temperture Turnip Pckging Swede Turnip Swede Turnip Swede Turnip Dys Temperture Pckging Dys Temperture Pckging Swede Turnip Swede Turnip Swede Turnip 5 d 10 d 5 d 10 d Whiteness (the higher the score the less enzymtic rowning) 5 o C 10 o C Pckging Effect of time, temperture nd pckging on qulity
PROCESSING OF ROOT VEGETABLES Peeling Cutting ± Wshing Centrifugt. ±Pre-pckging tretment Pckging Vrition in the unit opertion Arsion peeling Knife cutting, Knife peeling slicing, dicing & shredding Chemicl tretments Physicl tretments Edile cotings Gs trnsmission rtes Effects on: The physicl properties Wounding & oxidtion Vpor exchnge Constituents & microil lod Lekge Enzymtic rowning Microil lod Moisture retention Qulity retention
RESEARCH NEEDS Appropriteness of cultivrs/colored types/tissue ge t processing. Gentle processing/efficient decontmintion to mintin sensory qulity nd sfety. Better methods to evlute the direct effects of processing on qulity.
CONCLUSIONS Root vegetles contin dietry fiers, sugrs nd phytochemicls. Are low in vitmin C. Peeling removes the protective skin so microorgnisms cn enter. Specific phytochemicls re removed. White lush develops in wounded tissue due to loss of moisture from the surfce. Hrsh hndling/iotic stress enhnce phenolic metolism.
CONCLUSIONS Fresh-cut root vegetles re prone to: - enzymtic rowning in white/light-colored tissue - white lush in drk-colored tissue - loss of rom nd flvor especilly in crrots, prsnips, root prsley nd celeric if finely cut nd wshed - loss of sweet tste if finely cut nd wshed - fermenttion if oxygen get too low in the pckge
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