Prediction of Cupping Quality from Organic Acids and Sugars in ...
Prediction of Cupping Quality from Organic Acids and Sugars in ...
Prediction of Cupping Quality from Organic Acids and Sugars in ...
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<strong>Prediction</strong> <strong>of</strong> <strong>Cupp<strong>in</strong>g</strong> <strong>Quality</strong> <strong>from</strong><br />
<strong>Organic</strong> <strong>Acids</strong> <strong>and</strong> <strong>Sugars</strong> <strong>in</strong> green<br />
Bean<br />
� M. C. Jackson, Ph.D., HARC<br />
� C. Nagai, Ph.D., HARC<br />
� C. Cavaletto, Ph.D., UH<br />
� S. Bittenbender, Ph.D., UH<br />
� S. Steiman, graduate assistant, UH
Objectives:<br />
1. Develop method for organic acid <strong>and</strong><br />
sugar analysis<br />
2. Determ<strong>in</strong>e organic acid content <strong>of</strong> green<br />
c<strong>of</strong>fee<br />
3. Use c<strong>of</strong>fee chemical pr<strong>of</strong>ile to predict<br />
quality <strong>of</strong> cupp<strong>in</strong>g
Experimental Approach<br />
� Differences with<strong>in</strong> a variety across locations<br />
� Parents <strong>and</strong> progeny <strong>in</strong> a s<strong>in</strong>gle location
Sampl<strong>in</strong>g Locations<br />
State -wide variety trials, <strong>in</strong>itiated <strong>in</strong> 1988<br />
Locations: (Bittenbender <strong>and</strong> Cavaletto) Varieties:<br />
Hawaii Typica, Red Catuai<br />
Yellow Caturra, Mokka<br />
Maui various<br />
Oahu<br />
Kauai
Compounds <strong>of</strong> Interest<br />
� Simple organic acids<br />
� Free <strong>Sugars</strong><br />
� Chlorogenic acids
<strong>Organic</strong> Acid Effects<br />
Compare organic acid content <strong>of</strong> c<strong>of</strong>fee <strong>from</strong> various varieties <strong>and</strong><br />
locations <strong>and</strong> attempt to correlate with organolepic properties as<br />
determ<strong>in</strong>ed by tra<strong>in</strong>ed cupp<strong>in</strong>g panel <strong>from</strong> UH.<br />
Organoleptic Properties <strong>of</strong> <strong>Organic</strong> acids <strong>in</strong> C<strong>of</strong>fee<br />
Acid Organoleptic Properties<br />
Formic Rounded. Some brightness on first <strong>of</strong> tongue. Positive effect.<br />
Acetic Bright sweet lime<br />
Lactic Initially bright, but fades quickly<br />
Phosphoric Adds brightness, acidity. Masks bitter attributes.<br />
Pyruvic Positive effect. Very Moderate. Not an acidic flavor.<br />
Mild lime, grape fruit<br />
Oxalic Turpeny<br />
Malic Bright, sweet, orange.<br />
Tartaric V<strong>in</strong>egar, fruity ferment. Not sweet, more sour.<br />
Citric Ferment, sour, fruity ferment, Round edge.<br />
Acidic but not overbear<strong>in</strong>g. Apple like.<br />
Qu<strong>in</strong>ic Bitter, dull. When added with acid, sweeter.
Effects <strong>of</strong> Free <strong>Sugars</strong><br />
� Sucrose, fructose, glucose<br />
� Dur<strong>in</strong>g the destruction <strong>of</strong> sucrose dur<strong>in</strong>g<br />
roast<strong>in</strong>g, organic acids formed (Lukesch, 1956,<br />
Crean, 1966, Nakabayashi, 1978)
Effects <strong>of</strong> Chlorogenic <strong>Acids</strong><br />
� Family <strong>of</strong> acids - comb<strong>in</strong>ations <strong>of</strong> caffeic, ferulic<br />
<strong>and</strong> qu<strong>in</strong>ic acids<br />
� 22 isomers have been identified<br />
� mono- <strong>and</strong> di-caeffeoylqu<strong>in</strong>ic acids (mCQAs <strong>and</strong><br />
di-CQAs)<br />
� High di-CQA l<strong>in</strong>ger<strong>in</strong>g, bitter, metallic aftertaste<br />
(Birsh et al., 1973).<br />
� mCQA : di-CQA molar ratio appears important to<br />
taste (Ohiokpehai et al., 1982)
St<strong>and</strong>ardized Wet Process
C<strong>of</strong>fee Preparation<br />
� Dried green bean – typical commercial<br />
practice<br />
� Freeze dry to uniform 0% moisture<br />
� Gr<strong>in</strong>d<br />
� Analyze
Method Development<br />
� Developed method to simultaneously determ<strong>in</strong>e<br />
simple organic acids <strong>and</strong> free sugars <strong>in</strong> a s<strong>in</strong>gle<br />
step<br />
� Ion exchange HPLC with two detectors (RI for<br />
sugars UV for organic acids)<br />
� Chlorogenic acids determ<strong>in</strong>ed<br />
us<strong>in</strong>g previously published<br />
methods with modifications
Typical HPLC Pr<strong>of</strong>ile <strong>of</strong> Simple<br />
<strong>Organic</strong> <strong>Acids</strong>
Typical HPLC Pr<strong>of</strong>ile <strong>of</strong> Free <strong>Sugars</strong>
Typical HPLC Pr<strong>of</strong>ile <strong>of</strong> Chlorogenic<br />
<strong>Acids</strong>
Roast<strong>in</strong>g, Gr<strong>in</strong>d<strong>in</strong>g <strong>and</strong> <strong>Cupp<strong>in</strong>g</strong>
<strong>Cupp<strong>in</strong>g</strong> Protocol<br />
� Each variety cupped <strong>and</strong> rated three separate<br />
times<br />
� Descriptors only used when same observation<br />
occurred on three separate occasions<br />
� Panel <strong>of</strong> tra<strong>in</strong>ed cuppers
Progress To Date<br />
� All samples harvested <strong>and</strong> processed, with a<br />
repeat harvest <strong>from</strong> same plots <strong>and</strong> trees <strong>in</strong> the<br />
follow<strong>in</strong>g year<br />
� <strong>Cupp<strong>in</strong>g</strong> <strong>and</strong> chemical analyses <strong>of</strong> first year<br />
samples completed<br />
� <strong>Cupp<strong>in</strong>g</strong> <strong>and</strong> chemical analyses <strong>of</strong><br />
second year samples now<br />
underway
What's Next<br />
� Project is almost complete<br />
� Statistical analysis to beg<strong>in</strong> soon to determ<strong>in</strong>e<br />
which (if any) compounds are statistically<br />
significant contributors to cupp<strong>in</strong>g pr<strong>of</strong>iles<br />
� Dissem<strong>in</strong>ation <strong>of</strong> results through publications
Potential Value <strong>of</strong> the Project<br />
� C<strong>of</strong>fee breed<strong>in</strong>g programs<br />
� C<strong>of</strong>fee orig<strong>in</strong><br />
� Adulteration<br />
� Chemical manipulation <strong>of</strong> green c<strong>of</strong>fee to<br />
enhance aspects <strong>of</strong> cupp<strong>in</strong>g pr<strong>of</strong>ile
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