WHEAT VARIETY GRADING BY SCORE ANALYSIS APLICATION

New 48 wheat varieties, harvested in 2016 are classified in four wheat quality groups (improvers, bread varieties, basic varieties, poor quality varieties), based on minimumlevelof crude protein content, sedimentation value, flour extraction, yield of bread volume and bread crumb quality.22.9 % of analyzed varieties met all the prescribed parameter values for grading into defined quality groups. The objective of the presentedstudywas to evaluate the quality of the different wheat varieties byintegrating physicochemical, rheological and bread characteristics ofwheat. Following 13 parameters:test weight, 1000 kernel weight, vitreousness, flour extraction, crude protein content, sedimentation value, wet gluten content, falling number, absorption, farinograph number of quality, extensograph area, yield of bread volume and bread crumb quality were subjected to score analysis. Outcomes may help in better differentiation the quality of wheat varieties.Score analisys has been estimated as a helpful mathematical tool for wheat grading.


INTRODUCTION
Wheat (Triticum aestivum spp.vulgare) is produced, consumed and traded in the world, planted at round ¼ agricultural areas.It is utilisedmainly as human food, less animal feed, but also in various industries, such as: chemical, pharmaceutical.The main application of wheat is bread production, which is a diatery staple for approximately 70 % of world population.In Serbia, around 90 % of wheat is used for bread and pastry production, thereforethe quality of wheat varieties is evaluated based on bread quality.The suitability for bread making of particular wheat variety is determined mainly by its genetic make-up.A wheat variety is more suitable for bread making when the ability of its proteins to form the dimensional networks of gluten during kneading is greater (Callejo et al., 2015).The two main factors governing wheat quality are variety and growth environment.Within the limits of environment, quality is influenced by characteristics that can be altered by breeding and is further modified during harvesting, drying, transportation and storage (Anjum et al., 2008).Comprehensive knowledge exists on the variability of gluten proteins, their inheritance and influence on gluten function properties, in contrast, the impacts of environmental factors and their interactions with genotype affecting gluten quality are still only scarcely understood (Aghagholzadeh, 2017).The task of wheat breeders is to develop new wheat varieties which, beside possessing an improved yield potential and disease resistance, have improved bread making quality.Studies have documented that environmental variations in gluten quality can be large and thus a great challenge for the milling and baking industry.The great share of varieties attributed with low quality at the market makes difficulties inmilling and baking industry (Živančev et al, 2016(Živančev et al, , Fišteš et al, 2017)).
It takes a lot from creating the new variety of wheat to the final product comprising: selection, recognition, testing in macro trials, classification into the technological groups, production, purchase, storage and finely processing (Šarić et al., 1995/96).
Long lasting system of wheat classification in Serbia (also in Yugoslavia) is based on distribution of varieties in three technological groups (improving varieties, bread varieties and basic varieties) based on six parameters: protein content, zelleny sedimentation value, flour extraction, yield of bread, yield of bread volume and score for crumb quality.Experience showed that yield of bread is considered to be a facultative one and doesn't limit the technological group.Table 1 point at the limiting values of six parameters (Šarić et al. 1995/96, 1998).It is worth emphasizing that there are two values for yield of volume and score for bread crumb quality bread which allow different grading of the same wheat variety.
Тhe objective of the presented study was to evaluate the quality of the different wheat varieties by integrating physicochemical, rheological and bread characteristics of wheat.Following 13 parameters: test weight, 1000 kernel mass, vitreousness, flour extraction, crude protein content, sedimentation value, wet gluten content, falling number, absorption, farinograph number ofquality, extensograph area, yield of bread volume and score for bread crumb quality were subjected to score analyis.Outcomes may help in more objective andbetter differentiation the quality of wheat varieties.Score analisys has been estimated as a helpful mathematical tool for wheat grading.

MATERIAL AND METHODS
Different 48 new wheat varieties which are going to be recognizedwere used in this study.Experiments were carried out on field trials according to regulatedproduction technology.Each wheat variety, used in this study, was grown at two research stations in Bačka region.Samples of 5kg grains were properly stored in store room until analyzed.

Methods
Grain samples were evaluated for milling and baking quality.Presented data are mean values for a new variety grown at two locations.

Physical properties
Weight of 1000 kernels, test weight or hectoliter weight and vitreousness were recorded according to Regulations about methods... (1988).Wheat sample was free of foreign material and broken kernels.

Wheat milling
The tempered wheat grains, free of foreign material and broken kernels, were milled in Quadrumate Senior Mill to obtain strait grade flour (break flour+reductionflour), (Kaluđerski, Filipović, 1998).
Bread making procedure Bread was baked in the accredited laboratory of the Institute of food Technology Novi Sad in Novi Sad according to the internal procedure for evaluating wheat varieties (Kaluđerski, Filipović, 1998).
Yield of bread and yield of bread volume are calculated using following formulas: (2) Sensory analysis of bread crumbwas conducted to determine score for bread crumb quality using panel members previously trained on bread characteristics.The best and the worst quality are scored as 7.0 and 0.0, respectively (Kaluđerski, Filipović, 1998).
Statistics Score analysis uses min-max normalisation of wheat quality parameters transforming them from their original unit system in new dimensionless system where further mathematical calculations with different types of quality parameters are applicable (Jayalakshmi and Santhakumaran, 2011).Maximum value of normalised score presents optimum value of all combined analysed parameters, indicating on optimum total quality.Three score calculation is proposed: Score 4 , Score 13 and Score 4+9 : where x k is: Protein content, Zeleny sedimentation value, Yield of bread volume (500ml), Bread crumb quality (5.0); where y n is: Test weight, 1000 kernel weight, Vitreousness, Protein content, Zeleny sedimentation value, Wet gluten content, Flour extraction, Falling number, Farinograph water absorption, Farinograph number of quality, Extensograph area, Yield of bread volume (500ml), Bread crumb quality (5.0); where z m is: Protein content, Zeleny sedimentation value, Yield of bread volume, Bread crumb quality; and q l is: Test weight, 1000 kernel mass, Vitreousness, Wet gluten content, Flour extraction, Falling number, Farinograph water absorption, Farinograph number of quality, Extensograph area.
For all three Scores calculations:

RESULTS AND DISCUSSION
Data for one year testing of a new wheat variety at recognition,grown at only two sites, are not enough reliable.Therefore real judgement of the technological quality, particularly safe grading into the technological groups of quality is of particular interest.In the usual procedure each grain sample is subjected to 17different tests resulting in 29 outcomming parameters defining milling and baking quality of wheat variety, but wheat grading is done based on five parameters,listed in Table 1.For this study 13 characteristic prameters which define miling and baking wheat charcteristics are taken into consideration.Theresults of 48 wheat varieties quality parameters are shown in supplementaryary material.Data in Table 2, point at wide range of selected parameters for wheat varieties.Concerning minimum limiting values listed in Table1, minimum values for protein content and yield of volume are lower than the limiting values for basic varieties while minimum flour extraction is very high, it is reaching the upper limit for bread quality group.Grading wheat variety solely based on one year testing in physico-chemical, rheological and functional characteristics is a great responsibility due to variations in genetic, seasonal and environmental factors (Kundu et al., 2017).Concerning five parameters listed in Table1, among 48 new varieties (data enclosed in supplementary) only 22.9 % of samples met all limiting valuesand that safely could be classified in an adequate technological group, Table 3.It isworth emphasizing that in this group only one sample belongs to the technological group of improving varieties and majority to the basic group.There arise question how to determine to which technological group of quality belong samples that are partly meeting limiting values.In this study nearly half (45.8 %) of tested samples had 4 quality parameters within limiting values and one with higher or lower value, 27.1 % of samples have three parameters within limiting values and other two with higher or lower values and finally 4.2 % of samples have three parameters within group limits, one parameter with higher and the other with lower limiting values, Table 3. Flour extraction was always either within limiting values for the group or higher.It was particularly characteristic for the varieties classified in the group out of lower limiting values.According to Aghagholizadeh et al. (2017) gluten proteins are mainly responsible for dough handling and loaf volume for bread quality.Characterization of wheat varieties for end product utilization is also experienced by Panghal et al. (2017).Consistent with above mentioned statements those 77.1 % of varietiesare graded assuming that either protein content or scores for bread crumb quality (choosing higher value) are responsible for grouping.The result that is presented in Table 4 summarizes two above mentioned ways of wheat grading.The main disadvantage of that grading procedure is that majority of samples were classified irregularly, i.e. by subjective judgment based on experience.This statement is supported by great share of improving varieties in the group having 3 quality parameters within limiting values and two with lower values.All these point at the need of upgrading and finding the more reliable system of wheat grading according to the technological quality.At this stage of investigation, hard work of wheat breeder has to be regularly judged.It is worth highlighting that of a particular interest is to adequately assessthe genetic potential of a new wheat variety, by objective grading those varieties that partly meet limiting values listed in Table1 into a certain technological group.One attempt to solve the problem of grading varieties into technological groups is applying scoreanalysis.Flour extraction, as being very high, can be considered as non-selective parameter.Thereforescore analysis is carried out on 4 parameters (Score 4 ) listedin Table1, which showed to be the most important for grouping of varieties (also assuming yield of bread as facultative).Datapresented in supplementaryary material point that Score 4 analysis contributed to objective grading of those varieties (77.1 %) listed in tab. 1 which don't fully fit into limiting values.In both cases,only percent of varieties graded as bread varieties is the same, but the share of improving varieties significantly decreased.Score 4 analysis also showed that the assumption that either protein content or crumb quality is responsible for grouping is not enough reliable.By Score 4 analysis more than 50 % of varieties are graded as basic varieties, while 6.2 and 10.4 % of varieties belongto group of improving varieties and varieties out of lower limiting values, respectively.High percent of varieties classified by Score 4 as basic varieties was the main reason of applying Scoreanalysis to all selected 13 parameters (Score 13 ) which characterize flour milling and baking attributes, also dough rheology, Table 2. Outcomming scoring is presented in Table 4.In the case score analysis is carried on 13 quality parameters (Score 13 ),contribution of test weight, thousand kernel weight, vitreusness, flour extraction, wet gluten content, falling number, water absorption, farinograph number of quality and extensograph area is obvious.By comparingScore 4 andScore 13 , it can be stated thatpercent of varieties graded in the groups changed.Percent of improving and basic varieties decreased contrary to the percent ofbread varieties and varieties characterized with low quality.Close insight in Score 13 order and label of each variety (data enclosed in supplementary) point that the influence of 9 parameters of quality is very high, even so high, that can disrupt grading of those varieties which have all quality parameters within limiting values.This observation also pointed at good wheat varieties differentiation according technological quality, emphasizing that among tested samples there is a small number (4.2%) of samples from the group of improving varieties,though lower values for yield of volume and score for crumb quality, Table1, were used in the statistics, thus pointing to the great contribution of those 9 parameters.Those parameters also contributed to changing limiting score values.Therefore, Score 13 point to the need of score analysis improving, too.One possibility is grading varieties by Score 13 and discuss limiting score values for technological groups and the other is presented by score 4+9 Table 4.
of bread ) • (Yield of dough ) Weight of dough

Table 1 .
Minimum limiting values for parameters of wheat quality which determine technological groups

Table 2 .
Minimum and maximum values of selected quality parameters of 48 wheat varieties

Table 4 .
Wheat varieties grading into technological groups of quality applying score analysis