Quality Preferences : USDA ARS

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Quality Preferences

May 23, 2011

Colleagues,

For the past eleven years many researchers and seed companies have contributed to the US Wheat Associates Overseas Varietal Analysis Program. The Wheat Quality Council has evaluated your breeding samples for an even longer time period. Thank you for your contributions to those important soft wheat marketing programs. Based on the results of those programs and a recent survey we are proposing a set of guidelines or targets for soft wheat quality in the eastern US.

Below is the draft of the quality targets for soft wheat in the eastern US. These targets for quality come directly from the samples you have provided over the years. In the past year and half, the Soft Wheat Quality Laboratory has hosted several trade teams and industry groups to review the compiled years of results of the Overseas Varietal Analysis and Wheat Quality Council. At the most recent research review, we conducted a survey of millers and bakers for preferences relating to soft wheat quality. The quality targets are based on the past ten years of industry evaluations and the survey. A further description of the survey of millers and bakers follows the draft targets.

We would welcome your feedback and questions on these quality targets. They are intended as a starting point for future breeding efforts. The Soft Wheat Quality Laboratory will continue to evaluate samples and build on your participation in the Overseas Varietal Analysis and Wheat Quality Council.

Thank you again for your collaboration in the Overseas Varietal Analysis and Wheat Quality Council.

Edward Souza
Research Leader - Soft Wheat Quality Laboratory

Table 1. Draft targets and preferences for soft wheat quality in the eastern US production zones. Targets based on flour milled on a long-flow experimental mill such as the Miag Multomat.
Measure		Unit	Target for weak gluten products	Target for strong gluten products	Comments
Grain	Grain protein	%	8.5 to 10.5	10.5 to 12.0	The high frequency of very low protein samples is a problem for some customers
Grain	Deoxynivalenol	Ppm	<1.0 ppm	<1.0 ppm	Lower levels are always preferred.
Milling	Straight grade	%	=73	=73	Larger values always preferred
	Break flour	%	=34	=32	Larger values usually preferred
	Flour protein	% 14%mb	7.0 to 9.0	9.0 to 10.5	Preferences vary greatly by customer
	Flour ash	% 14%mb	0.40	0.40	Greater ash values permitted for greater flour extraction rates
	Falling Number	sec	350	350	Smaller values permitted for specific products. Larger values usually preferred.
Solvent Retention	Water	%	53	53	Greater values permitted if needed for greater flour extraction or gluten strength
	Sodium carbonate	%	=71	=71	Lower values are preferred
	Sucrose	%	=88	=93	Lower values usually preferred
	Lactic acid	%	95	=105	Preferences vary by customer, generally modestly larger values are preferred
Flour Color	Brightness	L*	=93	=92	Proposed values based on Overseas Varietal Analysis feedback
Flour Color	Yellowness	b*	<7.0	<8.5	Proposed values based on Overseas Varietal Analysis feedback
Alveograph	P	mm	35	40	Smaller values preferred for weak gluten products. Larger permitted for strong gluten products.
	L	mm	=80	=120	Greater values preferred in almost all products
	W	(x10?4J)	=80	=100	Preferences vary by customer, generally moderately greater values are preferred
	P/L		0.9	0.4	Ratio is typically not heritable. The trait is of less importance than other quality traits
Farinograph	Absorption	%	52	54	Greater values permitted if needed for greater flour extraction or gluten strength
Farinograph	Stability	BU	2.1	=4.2	Greater values usually acceptable but only necessary for strong gluten products
Wire-cut Cookie	Diameter	cm	=16.0	15.5	Greater values usually preferred. Of lesser importance for strong gluten products
Wire-cut Cookie	Spread factor	cm/mm	=0.75	0.70	Greater values usually preferred. Of lesser importance for strong gluten products

Quality Targets for Soft Wheat - A Survey for the AACC Cincinnati Section and the USDA Soft Wheat Quality Laboratory. USDA-ARS Soft Wheat Quality Laboratory

Summary: We surveyed end-users as part of the AACC Cincinnati Section meeting in March 2011 to build a broad picture of the uses of soft wheat and the type of flour required by customers for milling and baking. A soft red winter wheat team from US Wheat Associates was also present. A description of the survey and the methods is at the end of the report. A total of 26 surveys were returned. The survey presented current quality of flour as measured at the Soft Wheat Quality Laboratory (SWQL) using the Miag Multomat long-flow flour mill. Each respondent rated quality measures as important or not important and then was asked their preference for a larger, smaller, or current value for each trait. The question was asked separately for flours used for products typically manufactured with 1) low protein or weak gluten and 2) high protein or strong gluten.

Results: Milling yield and falling number (a-amylase) were rated as the most important quality traits for both types of flour (Figure 1). Increased flour yield was preferred for both strong gluten grain (Table 2) and weak gluten grain (Table 3). Falling number, a measure of pre-harvest sprouting, is important for flour specifications. Yet the actual value that can be tolerated varies greatly depending on the product as indicated by the variance of preferences (Table 2 and 3).

For weaker gluten flours, cookie quality traits were the next most important quality factor. For strong gluten flours, Farinograph traits and other measures of gluten strength were the next most important. Solvent retention capacity (SRC) tests or Alveograph measures were less important for both types of flour because end users tended to prefer one or another of the tests (Figure 1).

For stronger gluten flour, end users were generally satisfied with the current target grain and flour protein concentration (Table 2). Grain should typically have greater flour yield and stronger gluten than values given in Table 2. To obtain the greater flour yield some customers appear willing to accept greater flour ash concentration. Yet, preferences for flour ash level varied among customers more than for the other traits, as indicated by the variance of preferences (Table 2). Similarly, greater water absorption and Alveograph P values often are found in stronger gluten wheat samples. Some customers appear to tolerate modestly larger values for these traits, if it results in greater gluten strength.

Lower protein grain samples should, like the high protein samples, have greater flour yield (Table 3). Yet, users of low protein flour also place significant importance on recovery of flour from the break rolls, with greater flour yield from the break rolls generally preferred. Customers would prefer to have larger diameter and thinner stack height on cookies. Low protein flour users, on average, prefer to have somewhat stronger gluten wheat, as indicated by the preference responses to lactic acid SRC (+0.12), Alveograph W (+0.08) and Farinograph stability (+0.04, Table 3). Yet the preference for greater gluten strength in low protein products was smaller than for high protein products.

Respondents to the survey were asked for additional guidance to form soft wheat quality targets. The most common written specifications were requests for additional baking product tests including sugar-snap cookies, pancakes, various cake styles, and crackers. The most common suggestions for additional information concerned Fusarium/DON levels and flour color. Flour brightness and yellowness has a strong genetic component but also is influenced by extraction rate and protein concentration. Although it was not part of the survey, we have data available from the Overseas Varietal Analysis for flour color. Proposed values are included in the draft targets.

Draft Targets: Based on the results of the survey, we are proposing draft quality targets for soft wheat (See the Table 1). The numbers reflect the values measured at the SWQL on the Miag mill for soft wheat in the eastern US. Some of the numbers have been changed in the direction of values supported by strong consistent opinions in the survey. In addition to the draft targets, we are including comments to add context to the targets. That is, which values are consistently desirable and which have significant variation among customers? When preferences are strong which direction should the quality of new wheat cultivars move in order to improve the overall quality of the crop? It is our hope that breeders will use targets to select future varieties and industry will plan future research based on the importance assigned to specific traits. We intend that these targets should be critiqued and improved over the next several years. Please send your comments and recommendations to the Soft Wheat Quality Laboratory for inclusion into the next round of draft targets.

Figure 1. Importance of different quality traits to end-users in a survey conducted in 2011, Wooster OH. Survey participants were asked to rate quality separately for low protein/weak gluten flour products and high protein/strong gluten products.

Table 2. Survey for Soft Wheat Quality Targets of *HIGH PROTEIN* or *STRONG GLUTEN* Wheat.
Measure		Unit	Average value measured at SWQL	Importance (%)	Preference¹	Variance of preference²
Grain	Grain protein	%	11.6	0.58	0.00	0.24
Milling	Straight grade	%	73.5	0.77	0.50	0.42
	Break flour	%	32.3	0.58	0.23	0.42
	Flour protein	% 14%mb	9.8	0.58	0.04	0.36
	Flour ash	% 14%mb	0.40	0.42	0.12	0.51
	Falling Number	sec	377	0.69	0.00	0.32
Solvent Retention	Water	%	53	0.58	0.19	0.32
	Sodium carbonate	%	71	0.46	-0.04	0.28
	Sucrose	%	93	0.38	-0.08	0.23
	Lactic acid	%	105	0.46	0.23	0.34
Alveograph	P	mm	36	0.46	0.23	0.18
	L	mm	122	0.46	0.08	0.23
	W	(x10?4J)	107	0.50	0.27	0.20
	P/L		0.39	0.38	0.04	0.12
Farinograph	Absorption	%	53.2	0.62	0.27	0.36
Farinograph	Stability	BU	4.2	0.58	0.19	0.32
Wire-cut Cookie	Diameter	cm	15.8	0.46	0.12	0.35
Wire-cut Cookie	Spread factor	cm/mm	0.74	0.38	0.04	0.28
1. Positive values for preferences indicates on average more respondents preferred a larger value than the average value for high protein samples measured at the SWQL. Negative values indicate a preference for smaller values than measured at the SWQL. The larger the absolute value, the stronger the preference. 2. Variance of the preference indicates the uniformity of responses. Larger values indicate that customers are less uniform in their preferences for quality targets.

Table 3. Survey for Soft Wheat Quality Targets of *LOW PROTEIN* or *Weak GLUTEN* Wheat.
Measure		Unit	Average value measured at SWQL	Importance (%)	Preference¹	Variance of preference²
Grain	Grain protein	%	9.1	0.42	0.19	0.24
Milling	Straight grade	%	73.7	0.88	0.77	0.18
	Break flour	%	33.9	0.69	0.50	0.26
	Flour protein	% 14%mb	7.7	0.62	0.27	0.44
	Flour ash	% 14%mb	0.4	0.54	0.12	0.51
	Falling Number	sec	376	0.81	-0.12	0.35
Solvent Retention	Water	%	53	0.58	0.08	0.39
	Sodium carbonate	%	70	0.42	0.00	0.24
	Sucrose	%	88	0.38	0.04	0.20
	Lactic acid	%	93	0.38	0.12	0.27
Alveograph	P	mm	35	0.46	-0.08	0.15
	L	mm	84	0.42	0.08	0.23
	W	(x10?4J)	88	0.46	0.08	0.23
	P/L		93	0.35	-0.12	0.19
Farinograph	Absorption	%	51.8	0.50	0.08	0.31
Farinograph	Stability	BU	2.1	0.50	0.04	0.20
Wire-cut Cookie	Diameter	cm	16.0	0.69	0.35	0.32
Wire-cut Cookie	Spread factor	cm/mm	0.77	0.65	0.27	0.36
1. Positive values for preferences indicates on average more respondents preferred a larger value than the average value for high protein samples measured at the SWQL. Negative values indicate a preference for smaller values than measured at the SWQL. The larger the absolute value, the stronger the preference. 2. Variance of the preference indicates the uniformity of responses. Larger values indicate that customers are less uniform in their preferences for quality targets.

Methodology

Survey: The AACC Cincinnati Section and the Soft Wheat Quality Laboratory surveyed the annual section meeting at Wooster Ohio, on March 8th 2010. Approximately 90 people from the domestic milling and baking industry, wheat breeders, and a US Wheat Associates Soft Red Winter Wheat Trade Team were in attendance at the meeting. Prior to completion of the survey instrument, a facilitated discussion reviewed uses of soft wheat, specific quality measurements, and terminology related to soft wheat. Product uses were divided into those requiring 1) weak gluten or small protein concentration and 2) strong gluten or large protein concentration. Participants were then asked to rate the importance of each quality test. Participants had three choices: 1) important, 2) not important, and 3) don't know. The questions were repeated for weak gluten applications and strong gluten applications. Participants were presented with the specific values measured at the SWQL for the two classes of flour (small or large protein concentration). Participants were asked for their preference for each quality trait. Based on the current measured value in the survey, does the participant prefer larger values for a quality trait? Participants were given three choices for preference on each quality trait: a greater value is preferred, a smaller value is preferred, and the current value is OK)? Facilitators described each quality test during the session and answered about the survey. Translators were available for the international trade team. Participants in the survey worked together as teams in some cases based on site of employment and in many cases prepared only one response per business. A total of 26 surveys were collected at the end of the session.

Interpretation of Surveys: For importance of quality measures, we assumed that if a quality measure was important to a customer, they would have an opinion about the measure. Therefore uncompleted questions and 'don't know' answers were counted the same as 'not important' for the purposes of summary statistics. Surveys were summarized by averaging each question across the 26 surveys, where the answer important was scored as '1' and unimportant (or blank/don't know) was scored as '0'. The summary statistic is therefore a percent of respondents who perceived a specific quality trait as important. For preference surveys, we assigned numerical values to the survey answers. Greater values were scored as '+1'. A preference for a smaller value for the quality trait was scored as '-1'. If the answer was blank or 'OK' we scored the answer as '0'. We assumed that if a trait were important to the participant they would know the values and have a specific opinion or preference about the quality trait. Therefore we scored blanks as the quality trait being 'OK' because the value was not important to the customer and likely any value would be satisfactory.

Preparation of the Quality Values used in the Survey: The Soft Wheat Quality Laboratory has milled over 200 samples of grain for commercial evaluation over the past 11 years. These samples were milled on a 10 flour stream, Miag Mill and submitted to overseas and domestic millers for their evaluation. We will use the information on these samples to develop a guide on future quality work.

We have two tables of average quality measured on wheat samples for the past 11 years. One table has quality for high protein samples (average quality of the top third of samples with the greatest protein concentration, ~11.5% grain protein). The second table gives the average measured quality for grain samples with the lowest protein (average ~9.0%).
How do specific quality measures affect your work? Mark each quality measure as either important or not important for your business or laboratory. (+ if important / 0 if not important or do not know).
What level of quality would you like? Please give a preference for a quality level. If you prefer that the quality measure be greater than the average value mark a '+'. If less mark the row with a '-'. If the value is OK or you don't have a standard for the quality measure mark it '0'.

U.S. DEPARTMENT OF AGRICULTURE

Corn, Soybean and Wheat Quality Research: Wooster, OH