Statistical Evaluation of Dynamic Changes of ‘Idared’ Apples Colour During Storage

Colour changes on fruit during storage from brighter to darker nuances are caused by chemical reactions which oft en have degradative changes as a consequence. In this paper, evaluation of colour changes was done in CIE Lab colour model by using Minolta colorimeter CR-300 and in RGB colour model by applying digital image analysis method. In the aim of increasing of sample representativity analyzed apples were taken from different positions on trees and from different trees in orchard that was planted in 1983. Apples were harvested at a big commercial orchard in two different harvest times during one season. 30 apple pieces of Idared cultivar were analyzed immediately after harvest and periodically during storage for 20 weeks at 0 oC and 85-88% relative humidity. Apple temperature of all analyzed samples during storage period was T=0±0.4 oC. Mean colour change of apple skin determined in CIE Lab was ΔEab=1.53, while in RGB color model was ΔERGB=1.81. Total apple skin colour changes in Lab colour model was ΔEab=5.90, while in RGB colour model was ΔERGB=8.48. Both methods showed apple skin colour changes in the same way. Correlation between results was found to be 0.32 (p<0.05)

Primjena faktorske analize i modeliranja za brzu procjenu kakvoće hrvatskih kultivara pšenice s različitim značajkama glutena

Factor analysis and multivariate chemometric modelling for rapid assessment of baking quality of wheat cultivars from Slavonia region, Croatia, have been applied. The cultivars Žitarka, Kata, Monika, Ana, Demetra, Divana and Sana were grown under controlled conditions at the experimental field of Agricultural Institute Osijek during three years (2000–2002). Their quality properties were evaluated by 45 different chemical, physical and biochemical variables. The measured variables were grouped as: indirect quality parameters (6), farinographic parameters (7), extensographic parameters (5), baking test parameters (2) and reversed phase-high performance liquid chromatography (RP-HPLC) of gluten proteins (25). The aim of this study is to establish minimal number (three), i.e. principal factors, among the 45 variables and to derive multivariate linear regression models for their use in simple and fast prediction of wheat properties. Selection of the principal factors based on the principal component analysis (PCA) has been applied. The first three main factors of the analysis include: total glutenins (TGT), total ω-gliadins (Tω-) and the ratio of dough resistance/extensibility (R/Ext). These factors account for 76.45 % of the total variance. Linear regression models gave average regression coefficients (R) evaluated for the parameter groups: indirect quality R=0.91, baking test R=0.63, farinographic R=0.78, extensographic R=0.95 and RP-HPLC of gluten data R=0.90. Errors in the model predictions were evaluated by the 95 % significance intervals of the calibration lines. Practical applications of the models for rapid quality assessment and laboratory experiment planning were emphasized.U radu je primijenjena kemometrijska analiza za brzu i jednostavnu ocjenu pekarske kakvoće kultivara pšenice uzgojenih u Slavoniji (Hrvatska). Analizirani su kultivari Žitarka, Kata, Monika, Ana, Demetra, Divana i Sana iz kontroliranog uzgoja tijekom 2000-2002. godine. Kakvoća je pšenice analizirana mjerenjem 45 kemijskih, fizikalnih i biokemijskih parametara. Mjereni su parametri svrstani u ove skupine: indirektni parametri kakvoće, farinografski i ekstenzografski, parametri pokusnog pečenja kruha, te RP-HPLC parametri glutena. Svrha je istraživanja bila određivanje minimalnog broja varijabli (tri vodeća faktora), između 45 mjerenih veličina, na osnovi kojih se multivarijantnim modelom mogu jednostavno i brzo procijeniti sva analizirana svojstva pšenice. Primijenjena je kemometrijska analiza glavnih komponenata (PCA) za određivanje vodećih faktora. Analizom su određena tri vodeća faktora: ukupni glutenini TGT, ukupni ω-glijadini (Tω-), te omjer između otpora i rastezljivosti tijesta (R/Ext), kojima je objašnjeno 76,45 % od ukupne varijance svih eksperimentalnih podataka. Linearni regresijski modeli imaju ove prosječne vrijednosti koeficijenata korelacije za pojedine skupine: indirekti parametri kakvoće R=0,91; farinografski R=0,78; ekstenzografski R=0,95; parametri pokusnog pečenja kruha R=0,63, te RP-HPLC parametri glutena R=0,90. Istaknuta je važnost primjene modela za brzu procjenu kakvoće pšenice, a i za planiranje eksperimentalnog rada

Quality of wheat cultivars created at the Agricultural Institute Osijek in relation to high molecular weight glutenin subunits (HMW – GS) composition

Abstract Background and Purpose: The objective of this study was to estimate the effect of high molecularweight glutenin subunits(HMW-GS) composition of the Glu-1 loci on the quality of winter wheat cultivars created at the Agricultural Institute Osijek. Materials and Methods: Ten winter wheat cultivars were grown in 4 different locations during two years in a randomized complete block (RCB) experimental design with three repetitions at each location. Samples were collected and subjected to quality analysis and determination of HMW-GS composition by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Results: Considering theHMW-GS composition, the most frequent subunit at the Glu-A1 locus was N, at the Glu-B1 locus 7+9 and at the Glu-D1 locus 2+12. The analyzed cultivar Demetra, with subunits 5+10 at the Glu-D1 locus, has shown the best bread-making quality. Among cultivars with subunits 2+12 at the Glu-D1 locus, the cultivars with subunits 7+8 at the Glu-B1 locus have shown on average better characteristics of gluten strength with regard to higher values of Gluten Index and resistance to exstensibility ratio (R/Ext). The results of the linear correlation between quality parameters and HMW-GS composition, expressed as the Glu-1 score, have shown the most significant (P<0.05) influence ofHMW- -GS on Gluten Index r=0.42), dough energy (r=0.48) and dough maximum resistance (r=0.47). Conclusions: These results indicated that the presence of HMW-GS 5+10 and 7+8 contributes to higher bread-making quality of analyzed cultivars. TheHMW-GS composition has predictive value in quality analysis, therefore, the composition ofHMW-GS at the Glu-1 loci has to be taken into consideration when parents for a bread wheat breeding programme are chosen

The Relation between Dough Rheology and Bread Crumb Properties in Winter Wheat

The present paper is focused on rheology dough properties of winter wheat cultivars in relation to bread crumb properties. The rheological characteristics of wheat fl our were evaluated by using Farinograph and Extensograph tests. The image analysis for bread crumb grain assessment was applied as alternative technique for more rapid and efficient measurement of bread characteristics. The highest significant positive correlation (P<0.05) was found between bread crumb properties and extensographic parameters: dough energy, maximum dough resistance and resistance to extensibility ratio. Cultivars ‘Klara’, ‘Barbara’, ‘Žitarka’ and ‘Golubica’ have shown finer and uniform bread crumbs with regard to optimal dough physicochemical characteristics

The Relation between Dough Rheology and Bread Crumb Properties in Winter Wheat

The present paper is focused on rheology dough properties of winter wheat cultivars in relation to bread crumb properties. The rheological characteristics of wheat fl our were evaluated by using Farinograph and Extensograph tests. The image analysis for bread crumb grain assessment was applied as alternative technique for more rapid and efficient measurement of bread characteristics. The highest significant positive correlation (P<0.05) was found between bread crumb properties and extensographic parameters: dough energy, maximum dough resistance and resistance to extensibility ratio. Cultivars ‘Klara’, ‘Barbara’, ‘Žitarka’ and ‘Golubica’ have shown finer and uniform bread crumbs with regard to optimal dough physicochemical characteristics

Kemometrijska analiza udjela visokomolekularnih glutenina i struktura kruha od hrvatskih sorata pšenice

The aim of this work is to investigate functional relationships among wheat properties, high molecular mass (weight) (HMW) glutenin subunits and bread quality produced from eleven Croatian wheat cultivars by chemometric analysis. HMW glutenin subunits were fractionated by sodium dodecylsulfate polyacrylamid gel electrophoresis (SDS-PAGE) and subsequently analysed by scanning densitometry in order to quantify HMW glutenin fractions. Wheat properties are characterised by four variables: protein content, sedimentation value, wet gluten and gluten index. Bread quality is assessed by the standard measurement of loaf volume, and visual quality of bread slice is quantified by 8 parameters by the use of computer image analysis. The data matrix with 21 columns (measured variables) and 11 rows (cultivars) is analysed for determination of number of latent variables. It was found that the first two latent variables account for 92, 85 and 87 % of variance of wheat quality properties, HMW glutenin fractions, and the bread quality parameters, respectively. Classification and functional relationships are discussed from the case data (cultivars) and variable projections to the planes of the first two latent variables. Between Glu-D1y proportion and the bread quality parameters (standard parameter loaf volume and bread crumb cell area fraction determined by image analysis) the strongest positive correlations are found r = 0.651 and r = 0.885, respectively. Between Glu-B1x proportion and the bread quality parameters the strongest negative correlations are found r =-0.535 and r = –0.841, respectively. The results are discussed in view of possible development of new and improvement of existing wheat cultivars and optimisation of bread production.Svrha je rada istražiti me|usobnu ovisnost svojstava pšenice, udjela visokomolekularnih podjedinica glutenina (HMW) i kakvoće kruha proizvedenih od jedanaest hrvatskih sorata pšenice primjenom kemometrijske analize. Podjedinice HMW glutenina frakcionirane su natrijevim dodecilsulfat poliakrilamid gel-elektroforezom (SDS-PAGE), a zatim analizirane »scan« denizitrometrom radi određivanja frakcija HMW glutenina. Svojstva pšenice određena su sa četiri varijable: udjel proteina, vrijednost sedimentacije, količina vlažnog glutena i glutenski indeks. Kakvoća je kruha ocijenjena standardnim mjerenjem volumena kruha, a vizualna kvaliteta kriške kruha utvrđena je s osam parametara dobivenih računalnom analizom slike. Matrica podataka s 21 stupcem (mjerene varijable) i 11 redaka (sorte pšenice) analizirana je da bi se odredio broj latentnih varijabla. Ustanovljeno je da prve dvije latentne varijable objašnjavaju 92, 85 i 87 % varijance skupova podataka za kakvoću brašna, udjele frakcija HMW glutenina i kakvoće kruha. Projiciranjem na plohu prvih dviju latentnih varijabla razmotrena je klasifikacija i međusobna ovisnost sorata pšenice. Utvrđeno je da postoji najveća pozitivna korelacija između udjela D1y glutenina i kakvoće kruha (standardnim postupkom određivanja volumena i ukupne površine šupljikavosti kruha određene računalnom analizom slike), odgovarajuće vrijednosti su r = 0,651 i r = 0,885. Najveća negativna korelacija postignuta je između udjela Glu-B1x glutenina i kakvoće kruha, odgovarajuće su vrijednosti r = – 0,535 i r = – 0,841. Razmatrane su implikacije dobivenih rezultata za mogući daljnji razvoj i poboljšanje sorata pšenice i optimiranje procesa proizvodnje kruha

Optimisation of the Daily Nutrient Composition of Daily Intakes During Gestation

An appropriate lifestyle and diet of pregnant woman during prenatal development contribute to the proper development of a foetus. Since the third month of pregnancy, physical activity should follow the metabolic needs. In this paper, linear programming has been applied in meal planning according to the guidelines recommended for women aged 19 to 30, with emphasis on nutrient intake during all nine months of pregnancy. Data used as the nutritional composition are based on the seven-day supply, where each day consisted of 4 meals; breakfast, lunch, dinner and snack. Linear optimization was carried out using the LINDO program. The program included 28 variables and 20 constraints; energy, water, proteins, fats, carbohydrates, cholesterol, dietary fi bres, vitamins soluble in fats; A, D, water-soluble vitamins, B1, B2, niacin, B6, folic acid, B12, C, and minerals; calcium, iron, magnesium, and sodium. The results show that well-balanced, diverse and regular diet can be offered for pregnant woman based on prescribed guidelines providing adequate amounts of nutrients without taking additional supplements. The sensitivity analysis indicated that the menu planning has some limitations regarding the chosen foods in a weekly menu. Especially in the 3rd trimester it is important to include foods rich with folic acid, magnesium and iron

Primjena faktorske analize i modeliranja za brzu procjenu kakvoće hrvatskih kultivara pšenice s različitim značajkama glutena

Factor analysis and multivariate chemometric modelling for rapid assessment of baking quality of wheat cultivars from Slavonia region, Croatia, have been applied. The cultivars Žitarka, Kata, Monika, Ana, Demetra, Divana and Sana were grown under controlled conditions at the experimental field of Agricultural Institute Osijek during three years (2000–2002). Their quality properties were evaluated by 45 different chemical, physical and biochemical variables. The measured variables were grouped as: indirect quality parameters (6), farinographic parameters (7), extensographic parameters (5), baking test parameters (2) and reversed phase-high performance liquid chromatography (RP-HPLC) of gluten proteins (25). The aim of this study is to establish minimal number (three), i.e. principal factors, among the 45 variables and to derive multivariate linear regression models for their use in simple and fast prediction of wheat properties. Selection of the principal factors based on the principal component analysis (PCA) has been applied. The first three main factors of the analysis include: total glutenins (TGT), total ω-gliadins (Tω-) and the ratio of dough resistance/extensibility (R/Ext). These factors account for 76.45 % of the total variance. Linear regression models gave average regression coefficients (R) evaluated for the parameter groups: indirect quality R=0.91, baking test R=0.63, farinographic R=0.78, extensographic R=0.95 and RP-HPLC of gluten data R=0.90. Errors in the model predictions were evaluated by the 95 % significance intervals of the calibration lines. Practical applications of the models for rapid quality assessment and laboratory experiment planning were emphasized.U radu je primijenjena kemometrijska analiza za brzu i jednostavnu ocjenu pekarske kakvoće kultivara pšenice uzgojenih u Slavoniji (Hrvatska). Analizirani su kultivari Žitarka, Kata, Monika, Ana, Demetra, Divana i Sana iz kontroliranog uzgoja tijekom 2000-2002. godine. Kakvoća je pšenice analizirana mjerenjem 45 kemijskih, fizikalnih i biokemijskih parametara. Mjereni su parametri svrstani u ove skupine: indirektni parametri kakvoće, farinografski i ekstenzografski, parametri pokusnog pečenja kruha, te RP-HPLC parametri glutena. Svrha je istraživanja bila određivanje minimalnog broja varijabli (tri vodeća faktora), između 45 mjerenih veličina, na osnovi kojih se multivarijantnim modelom mogu jednostavno i brzo procijeniti sva analizirana svojstva pšenice. Primijenjena je kemometrijska analiza glavnih komponenata (PCA) za određivanje vodećih faktora. Analizom su određena tri vodeća faktora: ukupni glutenini TGT, ukupni ω-glijadini (Tω-), te omjer između otpora i rastezljivosti tijesta (R/Ext), kojima je objašnjeno 76,45 % od ukupne varijance svih eksperimentalnih podataka. Linearni regresijski modeli imaju ove prosječne vrijednosti koeficijenata korelacije za pojedine skupine: indirekti parametri kakvoće R=0,91; farinografski R=0,78; ekstenzografski R=0,95; parametri pokusnog pečenja kruha R=0,63, te RP-HPLC parametri glutena R=0,90. Istaknuta je važnost primjene modela za brzu procjenu kakvoće pšenice, a i za planiranje eksperimentalnog rada

Characterization of bread wheat cultivars (Triticum aestivum L.) by glutenin proteins

Glutenin polymers composed of HMW and LMW subunits are important contributors to the wheat end-use properties. Twenty-six winter wheat cultivars differing in bread processing quality were collected at the experimental fields of the Agricultural Institute Osijek, Croatia and Institute of the Field and Vegetable Crops Novi Sad, Serbia, in 2008/2009 season. The HMW glutenins composition and glutenin proteins content were determined by SDS-PAGE and RP-HPLC, respectively, with aim to determine the relationship between glutenin protein fractions and wheat quality properties. Significant differences were found between Croatian and Serbian cultivars in several quality attributes (GI, WA, DDT, DS and R/EXT) as well as in the content of total glutenins and LMW glutenins and GLI/GLU ratio. The dominant HMW subunits in analyzed cultivars were 2*, 7 + 9/7 + 8 and 5 + 10. Principal component analysis (PCA) confirmed the presence of association between HMW glutenins composition and GI, dough E, R and R/EXT, while the glutenins quantitative data showed pronounced relation with P, DDT, DS, E, R and R/EXT. GLI/GLU ratio had the opposite effect on these parameters

Benefits and Limitations of Lab-on-a-Chip Method over Reversed-Phase High-Performance Liquid Chromatography Method in Gluten Proteins Evaluation

RP-HPLC (reversed-phase high-performance liquid chromatography) is widely used to determine the amounts of the different gluten protein types. However, this method is time-consuming, especially at early stages of wheat breeding, when large number of samples needs to be analyzed. On the other hand, LoaC (Lab-on-a-Chip) technique has the potential for a fast, reliable, and automatable analysis of proteins. In the present study, benefits and limitations of Lab-on-a-Chip method over RP-HPLC method in gluten proteins evaluation were explored in order to determine in which way LoaC method should be improved in order to make its results more compliant with the results of RP-HPLC method. Strong correlation (P lt = 0.001) was found between numbers of HMW glutenin peaks determined by LoaC and RP-HPLC methods. Significant correlations (P lt = 0.05) were obtained between percentages of HMW and LMW glutenin subunits calculated with regard to total HMW + LMW area. Even more significant correlation (P lt = 0.001) was found when percentages of individual HMW areas were calculated with regard to total HMW. RP-HPLC method showed superiority in determination of gliadins since larger number and better resolution of gliadin peaks were obtained by this method