Fruit Composition & Quality - Aggie Horticulture
11/11/2016Fruit Composition & QualityJustin Scheiner, Ph.D.Assistant Professor andExtension Viticulture SpecialistWine Quality PotentialHigh quality fruit does not guarantee high quality wine,but low quality fruit guarantees low quality wine.1
11/11/2016Linking Viticulture to Wine FlavorWine 1,000 odorantsGrapes a few hundred odorantsPrimary flavorsSecondary flavorsWhat are the Chemical Components?ComponentMust(% by weight)Wine(% by c olics0.4-0.5%0.02-0.2%Aroma Compounds 0.02% 0.02%AlcoholAdopted from: Y. Margalit , Concepts in Wine Chemistry, 20122
11/11/2016Illustration by J. Koutroumanidis, WinetitlesConsumer preference has been moving toward wines with“ripe” characteristics.J. Alston et al. (JWE, 2011)3
11/11/2016Metrics for AciditypH reflects molar concentration of free protons– pH -log [H ] (e.g., a wine with a pH of 3 has 10x more free protons thana wine with pH of 4)Titratable acidity (TA) reflects total concentration of titratableH (pH bound H )OHOHOHCOOHHOOCCOOHOOCCOO-OOCH H OHTartaric acidOHOHBitartrateTartrateTitratable acidity is an excellentpredictor of perceived acidityFrom: Plane et al. 19804
11/11/2016Why do we care so much about pH?pH is critical for:–––––microbial stabilitycolormalolactic fermentationpreservatives (sulfur dioxide, sorbate)oxidationBisulfite(antioxidant)To achieve a “safe” level ofmolecular SO2 a white winewould require:13 ppm free at pH 3.040 ppm free at pH 3.5125 ppm free at pH 4.0200 ppm free at pH 4.3Molecular(antimicrobial &antioxidant)Juice/wine pH5
11/11/2016Concentration in JuiceOrganic Acids During Berry Development25malic acid g/Ltartaric acid Days After BloomTartaric Acid and PotassiumOHOHCOOHHOOCCOOHOOCOHTartaric acidK OHBitartrateH 6
11/11/2016Factors Affecting K ConcentrationMore K with longer hang-time, high water availabilityand water stress, and dense shading, high soil K From: Walker et al. 2012Juice pHJuice pHCluster thinning at fruit set – Cabernet t thinnedDays after veraisonC. McDonnell Wood (Ph.D. Dissertation, 2011)7
11/11/2016Components of QualitySkin:11% total tannin, longpolymers, all color,volatiles, potassiumSeeds:89% of total tannin, shortpolymersPulp: sugars, acids,potassiumMeasuring AciditypH: test strips, pH meter Calibrate meter regularlyProper storageReplace buffers annuallyTemperature correction8
11/11/2016Measuring Titratable AcidityTitratable acidity: acid/base titration Neutralize acid with a base (1:1 neutralization)Source of error: 0.1 N sodium hydroxide (NaOH) loses strength withair contact – inflated TA values Check with 0.1 N HClYeast Assimilable NitrogenIf you can measure TA then you can measure YANFormol titration1. Wine acids are titrated with 0.1 N NaOH2. Formaldehyde (37%) addition causes amino acidsand ammonium to release acid (H )3. Acids are titrated with 0.01 N NaOH9
11/11/2016SugarsFrom: N. Dokoozlian, Grape Berry Growth and DevelopmentMeasuring SugarsSoluble solids: 90% in ripe grapes are sugarsHydrometer: Specific gravity (density of juice / densityof water) Calibrated at room temperatureRefractometer: refractive index Calibrated at room temperature10
11/11/2016Use a Temperature Correcting RefractometerSolutions are more dense at lower temperaturesJuice TemperatureCorrected value at 20 C C / F BrixSpecific gravity16 / 60.8- 0.24- 0.001017 / 62.6- 0.18- 0.000818 / 64.4- 0.12- 0.000619 / 66.2- 0.06- 0.000421 / 69.8 0.06 0.001022 / 71.6 0.12 0.000823 / 73.4 0.18 0.000624 / 75.2 0.24 0.000438 / 100 1.020 / 68Rate of MaturationFunction of temperature, crop load, vine water statusand healthCluster thinning at fruit set – Cabernet t thinnedDaysafterafterveraisonDaysveraisonC. McDonnell Wood (Ph.D. Dissertation, 2011)11
neClusters/vineNot thinnedC. McDonnell Wood (Ph.D. Dissertation, 2011)1-bud spurs12
11/11/20161-bud spurs2-bud spursUnder-Pruned13
11/11/2016Divided canopy systems were developed for managing toomuch vigor14
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11/11/2016Cluster ThinningWhy: maintain balance, improve quality, reduce unevennessWhen: before veraison (reduce yield), end of veraison (reduceunevenness) Target least advanced clusters, weak shootsHedgingWhen: after shoots clear the top of the trellis, but beforethey droop over and shade the fruiting zone At a minimum, leave 15 mature leaves per shoot16
11/11/2016Don’t over-hedgeShoot PositioningWhy: minimize shoot overlap, improve spraypenetration, improve leaf sun exposureWhen: after thinning, when shoots reach first catchwire (for VSP systems), before tendrils becomestrongly attached Watch out for shoot breakage17
11/11/2016Leaf & Lateral RemovalWhy: improve cluster microclimateWhen: within a few weeks of fruit setFrom: Austin et al.18
11/11/2016Fungal Disease Reduces QualityLate Season Grape Berry Moth19
11/11/2016SamplingAccuracy Versus PrecisionA good analyst should havegood accuracy and precision. precision – random error accuracy – systematic error,difference between measuredmean and true valuepoor accuracy and poor precisiongood accuracy and good precisionpoor accuracy and good precision good mean accuracy and poor precision20
11/11/2016Vineyard Variability Vineyard variability leads to reduced qualityBetween vines: soil, vine age, frost damage, disease, pruningBetween clusters on the same vine: cluster position, vine stress,disease, frost damageBetween berries on the same cluster: sun exposure,shot berries, poor weather atbloom, micronutrient deficiency,disease, insect infestationBerry or Whole Cluster Samples?21
11/11/2016Sample vines randomly or by a grid system Avoid sampling from exterior vines (border rows, end vines)or abnormal vines Keep records and compare to previous years and harvest data If results do not correlate with harvest data, adjust samplingprocedureBerry SamplingBetter suited for small vineyards and early sampling Avoid border rows and end vines /- 1 Brix 200 berries (uniform vineyard) /- 0.5 Brix 500 berries– 5 berries per cluster on one cluster per vine– One berry from each side of the shoulder, middle, andbottom of the cluster (randomize side where sample istaken)22
11/11/2016Cluster SamplingAccounts for within cluster variability (5-7 Brix)Sample size should be related to the size of theblock and variability within the block– A uniform block of 5 acres, sample 20-25 clusters– A block with a high degree of variability, 25clusters– One randomly selected cluster per vine– Sample on both sides of the rowDo not determine maturity based on a single vine.23
11/11/2016Processing Sample Process samples as soon as possible (within a few hours) Try to duplicate actual winery processing– 300 mL of juice from 1 lb of fruit is approximately equivalent to160 gallons of juice/ton of fruitSeeds)- tannins- oilsSkin- aroma- tannins- color- cationsjscheiner@tamu.edu24
Cluster Sampling Accounts for within cluster variability (5-7 Brix) Sample size should be related to the size of the block and variability within the block –A uniform block of 5 acres, sample 20-25 clusters –A block with a high degree of variability, 25 clusters –One randomly selected cluster per vine
Course Title - Principles of Horticulture and production technology of fruit crops Credit hours - 3 (2 1) Lec.No. Topic / Lecture Page No. 1 Definitions of Horticulture-literal meaning, olden day‘s horticulture and modern horticulture. Divisions of horticulture-Pomology, olericulture ,floriculture (commercial
Monitoring Fruit Maturity: When color just begins to show along the suture, fruit should be mature in roughly 30 days. Begin measuring fruit internal pressure once fruit shows color. Warmer weather slows fruit maturity; cooler weather faster fruit maturity. Fruit lose 1 to 2 lbs fruit pressure per week and are mature at 3 - 4 lbs internal .
(page 4) and why grass might not be growing under your pecan trees (page 5). Donna Ward’s engaging Trowels & Tribulations article on page 12 offers more advice for spring garden-ing activities to take care of before summer arrives. Jan Brick shares why we should have the lovely shrimp plant in our gardens on page 13.
and multiple technical working groups. The assessment method has been tested with companies across a diverse set of product types, covering a wide range of sectors including: †Goods and services †Manufacturers, retailers and traders †Business-to-business (B2B) and business-to-consumer (B2C) †UK and international supply chains
The fruit of Silence is Prayer. The fruit of Prayer is Faith. The fruit of Faith is Love. The fruit of Love is Service. The fruit of Service is Peace. These five lines were written on St. Teresa of Calcutta's business cards. The card didn't have her name or the Missionaries of Charity written on it, just these simple words. On the back of the .
AGY 303 LECTURE NOTE FUNDAMENTALS OF HORTICULTURE Introduction Horticulture is derived from two Latin words: Hortus and Colere. Horticulture is a science that deals with the production and utilization of garden crops. Horticulture is divided into four branches. Floriculture: the science of production and utilization of ornamental plants
Aggie Card The Aggie Card is your official Texas A&M University ID. It shows your status as a member of the Aggie family. It is important for you to . Refunds are generated by Student Business Services and disbursed to you via the bank account of your choice. ESCI Heartland is our 3rd party servicer.File Size: 1MB
Fruit drink obtained by mixing two or more fruit juice pulp and purées from different kinds of fruit species 3.10 Fruit squash . The products shall be soft drinks beverage intended for human consumption which contains, fruit juice, fruit pulp or other edible parts of the fruits. It may be made from a .
