Remix and Remix-to-Peak Baking Methods: Effects of Fermentation Time and Salt on Baking Properties of a Canadian Bread Wheat

Can. lnsl. Faad Sci. Techno!. J. Vol. 17, No.4, pp. 260-265, 1984

RESEARCH

Remix and Remix-to-Peak Baking Methods: Effects of Fermentation Time and Salt on Baking Properties of a Canadian Bread Wheat K.R. Preston, E. Mydlo and R.H. Kilborn l Grain Research Laboratory Canadian Grain Commission 1404 - 303 Main Street Winnipeg, Manitoba R3C 3G8

Abstract

Canadian bread wheats. At the Grain Research Laboratory these tests have been used to monitor the baking quality of Canadian wheat cargoes, new crop composites, carlot composites and commercial flour samples. Various Canadian universities, Agriculture Canada laboratories and the Grain Research Laboratory have also used the Remix test and its variations (Remix-blend, Remix-to-peak, Remix-2Olo-salt, Remixno-bromate) to assess the baking quality of plant breeders' lines. In addition, these methods have been useful in research studies aimed at identifying wheat flour components responsible for baking quality (Orth and Bushuk, 1972; Preston and Tipples, 1980; Dexter et al., 1981). At present, however, little information has been published concerning the effects of varying ingredient levels and processing conditions on these baking procedures. Studies have, therefore, been initiated in our laboratory concerning these effects in order to obtain a better understanding of the Remix test and its variations and to obtain further information pertaining to the quality of Canadian bread wheats. In the present paper, the effects of varying fermentation time and salt level upon the mixing and baking properties of a Canadian red spring wheat flour with the Remix and Remix-to-peak methods have been studied.

The effects of varying fermentation time (0 to 285 min) and salt level (0.5 to 3.0070 NaCl) on the Remix and Remix-to-peak test baking properties of a Canadian wheat flour have been studied. Water absorption requirements for optimum handling properties were much more sensitive to fermentation time than to salt level, while dough mixing requirements showed the opposite effect. With the Remix procedure, increasing fermentation time or salt level reduced loaf volume, crust and crumb quality and total bread scores. With Remixto-peak procedure, where remixing requirements were optimized after fermentation, the effet of salt level was much less pronounced. At lower salt levels (0.5, 1.0 and 2.0%) loaf volumes and bread scores decreased after 105 min fermentation. With 3% salt optimum bread properties were obtained with fermentation times from 105 to 195 min.

Resume L'influence du temps de fermentation (0-285 min) et du niveau de sel (0.5 - 3% NaCl) sur les proprietes boulangeres d'une farine de ble canadien a ete etudiee ill'aide du test RemiX et du test Remix optimalise. Les besoins d'absorption d'eau pour des proprietes optimales de manutention furent beaucoup plus sensibles au temps de fermentation qu'au niveau de sel tandis que les besoins de malaxage de la pate furent ill'inverse. Dans Ie cas de la procedure Remix, Ie temps de fermentation etle niveau de sel furent inversement correles au volume de la miche, ilia qualite de la croOte et de la mie, et au pointage general du pain. Dans Ie cas de la procedure Remix optimalisee, oil les besoins de remalaxage furent optimalises apres la fermentation, I'influence du niveau de sel fut beaucoup moins evidente. Aux niveaux faibles de sel (0.5, 1.0 et 2.0%) les volumes de miches et les pointages du pain diminuerent apres une fermentation excedant 105 min. Au niveau de sel de 3%, les proprietes optimales du pain furent obtenues avec des temps de fermentation entre 105 et 195 min.

Materials and Methods Flour

The flour used in the present study was the same as that described in a previous study (Black et al., 1981). This straight grade flour was milled from a sample of No.1 Canada Western Red Spring (CWRS) wheat on the GRL Pilot Mill (yield = 73.7%) and had a protein content of 12.8% (N x 5.7), ash content of 0.39%, starch damage of 31 Farrand units and an amylograph peak viscosity of 560 BU. All results were calculated on a 14% moisture basis.

Introduction Since its introduction by Irvine and McMullan in 1960, the Remix baking test and variations thereof (Irvine and McMullan, 1960; Kilborn and Tipples, 1981) have played a major role in the assessment of IPaper No. 543 of the Grain Research Laboratory, Canadian Grain Commission, 1404 - 303 Main Street, Winnipeg, Manitoba R3C 3G8.

Copyright

(l

1984 Canadian Institule of Food Science and Technology

260

Table I. Effects of Fermentation Time and Sail Level upon Optimum Baking Absorption l with the Remix and Remix-toPeak Methods Sail Level 45 % Remix 0.5 65 1.0 65 2.0 65 3.0 65 Remix-to-peak 0.5 65 1.0 65 2.0 65 3.0 65 IAbsorption expressed as moisture basis).

Fermentation Time (min) 75

105 135 165 195 225 255 285

64 63 64 65

64 63 64 64

63 63 64 64

63 63 64 64

64 64 63 63 64 64 63 63 64 64 64 64 65 64 64 64 % water absorption

62 63 64 63

61 63 64 62

61 61 63 62

62 61 61 62 62 61 64 64 63 63 63 63 per 100 g flour

61 61 62 62 61 61 62 63 (14%

Baking Procedures The Remix and Remix-to-peak methods were performed according to the procedure of Irvine and McMullan (1960) as modified by Kilborn and Tipples (1981). The standard Remix ingredients included 100 g flour (14070 MB), 3.0 g compressed yeast, 2.5 g sugar, 1.0 g salt, 0.6 g malt syrup (60° Lintner), 0.1 g ammonium phosphate (monobasic), 1.5 mg (15 ppm) potassium bromate and water (based upon dough "feel" and machining properties at panning). Ingredients were mixed for 3.5 min in a GRL mixer (135 rpm). Doughs were then hand-punched, rounded, fermented at 30.0°C for 165 min and remixed for 2.5 min. Following an intermediate proof of 25 min, doughs were sheeted, molded and panned. After a 55 min final proof at 30.0°C, baking was carried out for 25 min at 221°C. Loaf volumes were measured by rapeseed displacement after the bread had cooled. Loaf appearance, crumb structure and crumb color were measured approximately 20 h after baking as described by Kilborn and Tipples (1981). Total bread scores were determined as described previously (Preston et al., 1982). For the standard Remix-to-peak method, ingredients and processing conditions were identical to the Remix method except that after 165 min fermentation, doughs were remixed to peak consistency. All experiments were carried out in duplicate. Standard deviations of duplicates for loaf volumes for both the Remix and Remix-to-peak methods were 10 cc. Mixing curves for measuring mixing time and energy requirements were obtained as previously described (Kilborn and Tipples, 1981).

Absorption. Fermentation Time and Salt Level To study the effect of fermentation time and salt level upon bread properties the following experiments were carried out:

Optimum Absorption: Optimum baking absorption, as assessed by "dough feel" at panning by an experienced operator, was determined with each combination of salt level and fermentation time for both the Remix and Remix-to-peak procedures. Salt levels studied included 0.5, 1.0, 2.0 Can. lnst. Food Sci. Technol. J. Vol. 17, No.4, 1984

Table 2. Effects of Fermentation Time and Salt Level upon Optimum Remix Time l with the RemiX-f.o-Peak Method at Optimum Absorption Fermentation Sail Level 45 75 105 135 165 % 0.5 2.7 3.0 3.0 2.8 2.7 3.3 3.5 3.5 3.4 3.7 1.0 2.0 4.0 4.3 4.3 4.8 5.2 4.2 4.9 5.0 6.0 6.4 3.0 ITime to reach peak consistency

Time (min) 195 2.8 3.3 5.0 6.3

225 2.5 3.2 4.7 5.7

255 2.0 2.8 4.9 6.2

285 2.4 3.1 4.6 5.7

and 3.0% based upon flour weight. Fermentation times for each salt level were varied from 45 to 285 min in 30 min intervals.

Constant Absorption: In cases where the effects of constant absorption upon dough and bread properties were studied, optimum baking absorption as assessed by "dough feel" at panning, was determined for each salt level for both the Remix and Remix-to-peak methods using the standard 165 min fermentation time. These absorptions were then used with other fermentation times which were varied from 45 to 285 min in 30 min intervals. For 0.5 and 1.0% salt, a constant absorption level of 63% was used for both the Remix and Remix-to-peak methods, while with 2.0 and 3.0% salt a constant absorption of 64% was used for both procedures.

Results and Discussion Table I shows the effects of fermentation time and salt level upon the optimum baking absorption of the CWRS wheat flour. Doughs processed by the Remix and Remix-to-peak methods showed similar (within 1 mL) baking absorptions at corresponding fermentation times and salt levels. Although there was a tendency for baking absorption to increase as salt level increased at longer fermentation times, the effect of fermentation time was more dramatic. As fermentation time was increased from 45 to 285 min there was an average decrease in optimum baking absorption of 4% with the two lower salt levels and 3% decrease with the two higher salt levels. Decreases in baking absorption with increasing fermentation time are well known and have been attributed mainly to the hydrolysis of damaged starch by amylolytic activity resulting in a decrease in dough water binding capacity (Halton, 1961; Tipples, 1969). The effects of fermentation time and salt level at optimum baking absorptions upon the Remix-to-peak times are shown in Table 2. With 0.5% salt, Remixto-peak times showed little change with fermentation time up to 195 min after which remix time decreased. A similar trend occurred with 1.0% salt, although the decrease in remix time was less evident at longer fermentation times. At higher salt levels, Remix-to-peak times were difficult to determine due to the greatly increased stability of the doughs to overmixing. However, at these higher salt levels (2.0 and 3.0%) there was an initial increase in remix time with increasing fermentation up to approximately 165 min folPreston et al. / 261

Table 3. Effects of Fermentation Time and Salt Level upon Mixing Energy Requirements with the Remix and Remix-lo·Peak Methods at Optimum Absorption Fermentation Time (min) Sail Level 45 75 105 135 165 195 225 255 % Remix' 0.5 3.6 3.5 3.4 3.4 3.4 3.6 3.5 3.4 1.0 3.5 3.4 3.2 3.2 3.2 3.1 3.0 3.2 2.0 2.5 3.1 3.0 2.5 2.6 2.4 2.5 2.6 3.0 2.7 2.7 2.5 2.4 2.2 2.4 2.7 2.5 Remix-to-Peak 2 0.5 4.0 4.3 4.0 3.8 3.7 3.9 3.6 2.9 1.0 4.2 4.4 4.3 3.8 4.3 3.7 3.8 3.2 2.0 4.7 4.9 5.2 5.3 5.4 4.8 4.4 5.1 3.0 4.8 5.4 5.8 7.0 7.3 7.1 6.0 7.2 'Energy input (Wh/kg) after 2.5 min remix 2Energy input (Wh/kg) to remix doughs to peak consistency

285 3.5 3.2 2.8 2.4 3.3 3.7 5.5 6.2

lowed by a decrease as fermentation time was further increased. As was expected, the well known "toughing" effect of salt upon gluten proteins was evident by the increase in optimum remix time required to bring about optimum dough development as salt levels were increased at constant fermentation time. Table 3 shows the effect of fermentation time and salt level upon mixing energy input with the Remixto-peak methods at optimum absorptions. With the constant 2.5 min remix time (Remix method), mixing energy input decreased with increasing salt levels. Although this result appears inconsistent with the "toughing" effect of salt, the reasons were evident from an examination of the mixing curves (not shown). During remixing, there was generally an initial drop in consistency followed by an increase as the dough was developed toward peak consistency. As salt level was increased, the initial drop in consistency became more pronounced and was followed by a more gradual rise in consistency. These effects resulted in a lower mixing energy input with higher salt levels after 2.5 min. At each salt level studied, fermentation time did not appear to have a significant effect upon mixing energy input with the 2.5 min remix time (Table 3). This was probably related to the use of optimum absorption levels for each fermentation time which maintained a constant ratio between dough solids and water. When doughs were processed at a constant absorption of 63.0070 for the 0.5 and 1.0% salt levels and at 64.0% for the 2.0 and 3.0% salt levels, mixing energy inputs decreased approximately 20% when fermentation time was increased from 45 to 285 min (data not shown). This decrease was probably related to an increase in "free" water which would reduce mixing efficiency (cause a "slack" dough). In parallel with the Remix-to-peak optimum remix times, the mixing energy consumption for optimum development increased as salt increased. As evidenced in Table 3, these differences became more pronounced as fermentation time increased. With the two lower salt levels optimum mixing energy input tended to decrease at longer fermentation times. This decrease was probably associated with the well known "mel262 / Preston et al.

lowing" effect of fermentation upon the gluten proteins (Bohn and Bailey, 1937; Hoseney et al., 1979). At the higher salt levels optimum mixing energy inputs were difficult to determine due to increased dough stability. However, in spite of this difficulty, data indicated that with 2.0 or 3.0% salt, optimum mixing energy input increased as fermentation time increased up to about 165 min after which there appeared to be a slight decrease. The effects were more pronounced with 3% salt. At present, the reasons for this initial increase in mixing requirements are not known. However, one possible explanation may be the "toughing" effect that gluten undergoes as pH is decreased in the presence of higher salt levels (Galal et al., 1978). Thus, although the "mellowing" effect of fermentation would tend to reduce mixing requirements at all salt levels, the decrease in pH due to acid production during fermentation in the presence of high levels of salt would tend to increase mixing requirements. Therefore, the magnitude of these opposing effects would determine whether mixing requirements decreased or increased as fermentation time was increased. Using constant absorption, the effects of salt level and fermentation upon mixing energy input with the Remix and Remix-to-peak methods were similar to that observed with the optimum absorption methods (data not shown). However, with constant absorption, mixing requirements were approximately 10-15% less with short fermentation times and 15-20% greater at the longer fermentation compared to results obtained at optimum absorption. The decrease in mixing requirements at shorter fermentation times was probably related to the "tighter" doughs which would absorb energy more efficiently. The greater mixing requirement at longer fermentation times was probably related to the excess water which "slackened" the dough and thus reduced mixing efficiency. The effect of fermentation time and salt level at optimum absorption upon loaf volume with the Remix and Remix-to-peak methods are shown in Figure 1 and 2 while data for loaf appearance, crumb structure and crumb color are given in Tables 4 and 5. With the Remix method, loaf volumes (Figure 1) decreased with fermentation time for each salt level although with the lower salt levels decreases were not evident until after 165 min. Much larger loaf volumes were obtained with the two lower salt levels than with the higher salt levels. These differences were probably due, in large part, to the longer mixing requirements of the latter (Table 2) resulting in undermixed doughs with the 2.5 min Remix time. With the Remixto-peak method (Figure 2), where doughs were mixed to peak consistency after fermentations, the effects of fermentation time at low salt levels were similar (Figure 2) to those obtained with the Remix method. This result was not surprising since the 2.5 min standard Remix time corresponded closely to optimum mixing requirements. With the higher salt levels loaf volume increased initially and then decreased with increasing fermentation time. As with the Remix method, lower J. Ins!. Can. Sci. Techno!. Aliment. Vol. 17, No.4, 1984

1.000

900

:::

:::

;:::>

;:::>

800

0> ~ 700

g

9

...

g 600

...--......-....

.........

............. _-~--

...-- ......................

5003!:-0-'--c':60,.--'--:9':-0-'---:1~20:-''---:cI50!:--'-:1~80:-'--:-21~0-'---:2=-'"4'''''0 -'--::2=-=70:-'

FERMENTATION TIME. min

..........

Fig. 2 Effects of fermentation time and salt level on Remix-to-peak loaf volume. Sodium chloride concentrations: 0.5070 = 0 - - 0 ; 1.0070 = . - - . ; 2.0070 = 0 - - 0 ; 3.0070 = . - -• .

FERMENTATION TIME. min

Fig. I Effects of fermentation time and salt level on Remix. Sodium chloride concentrations: 0.5% = 0 - - 0 ; 1.0070 = . - - . ; 2.0070 = 0 - - 0 ; 3.0070 = . - -• .

method (Table 5). This was not surprising since optimum remix times were similar to the standard 2.5 min Remix time. Remix loaf appearance, crumb structure and crumb color scores were considerably lower with the higher salt levels than corresponding values obtained at lower salt levels. These differences were probably due to inadequate dough development at high salt levels. With the Remix-to-peak procedure, where mixing requirements were satisfied, differences were less evident although the higher salt levels still gave lower scores except with longer fermentation times. This reversal of order at longer fermentation times is probably related to greater dough fermentation tolerance in the presence of higher salt levels. Although Remix loaf appearance, crumb structure and crumb color scores decreased with increasing fermentation times at high salt levels, Remix-to-peak scores increased with fermentation time up to approximately 165 min. Longer fermentation times had little effect upon loaf appearance and crumb structure whereas crumb color scores showed fairly large decreases.

loaf volumes were obtained at higher salt levels with the Remix-to-peak method (Figure 2). However, differences were much smaller, averaging less than 100 cc. Longer proofing times with the higher salt levels may have further reduced these differences. At longer fermentation times, differences became less evident while at the longest fermentation time, the higher salt levels gave the largest loaf volumes. This indicates that high salt levels may have imparted greater fermentation tolerance to the doughs. This view is consistent with the dough strengthening effect of salt (Bohn and Bailey, 1937; Fisher et al., 1949; Hlynka, 1962). Loaf appearance, crumb structure and crumb color score results are given in Tables 4 and 5. At low salt levels, Remix loaf appearance and crumb structure scores showed little change up to 195 min fermentation after which values decreased. Crumb color scores showed a similar trend although decreases in scores occurred after a shorter fermentation period. Identical results were obtained with the Remix-to-peak

Table 4. Effects of Fermentation Time and Sail Level upon Bread Characlerislics with the Remix Melhod al Optimum Absorption Fermentation Time (min)

Sail Level

% Loaf Appearance 0.5 1.0 2.0 3.0 Crumb Structure 1 0.5 1.0 2.0 3.0 Crumb Color 2 0.5 1.0 2.0 3.0

45

75

105

135

165

195

225

255

285

8.2 8.0 7.0 6.0

8.0 8.0 6.0 5.2

8.5 8.0 6.5 5.2

8.0 7.8 5.5 5.0

8.2 8.2 5.5 4.8

7.5 8.0 5.2 5.0

7.5 7.8 5.2 5.0

7.0 8.0 5.5 5.0

6.0 7.5 6.0 5.0

6.80 6.50 6.5cl 5.5cl

6.50 6.80 6.OcI 5.20

6.50 6.50 5.5cl 4.8co

6.50 6.80 5.2cl 4.2co

6.50 6.80 5.OcI 3.8co

6.20 6.80 4.8c 4.5co

6.2vo 6.50 4.5c 4.Oc

6.20 6.00 5.5cl 3.5co

5.5 6.00 5.Oc 3.Oco

7.5 7.0 6.0dy 5.5dy

7.5 6.8dy 6.0dy 5.0dy

7.5d 6.5d 6.0dy o 5.Ody

6.5d 6.5d 5.5dy 4.2gy

6.5d 6.Ody 5.5dy 4.0gy

6.0dy 5.5dy 5.0d 3.5gy

6.Ody 5.0dy 4.5d 3.0gy

6.0dy 6.Ody 3.5gy 2.5gy

5.Ody 5.5dy 3.0gy 2.0gy

IvO = very open; cI = closed; c = coarse; co = coarse and open 2d = dull; dy = dull yellow; gy = grey yellow Can. InSI. Food Sci. Technol. J. Vol. 17, No.4, 1984

Preston et al. / 263

Table 5. Effects of Fermentation Time and Salt Level upon Bread Characteristics with the Remix-to-peak Method at Optimum Absorption Fermentation Time (min)

Salt Level

%

45

Loaf Appearance 0.5 8.2 1.0 8.0 2.0 7.5 3.0 7.0 Crumb Structure I 0.5 6.50 1.0 6.80 2.0 6.80 3.0 6.0cl Crumb Color l 0.5 7.5 1.0 7.5 2.0 7.5 3.0 6.0dy Isee Table 4 for abbreviations

75

105

135

165

195

225

255

285

8.0 8.2 7.8 8.0

8.5 8.5 8.0 8.0

8.0 7.8 8.2 8.0

8.5 8.5 7.8 8.0

7.5 8.5 7.8 8.2

7.5 8.2 7.5 8.2

7.0 8.0 8.0 7.8

6.0 7.2 7.2 7.5

6.50 6.50 7.0cl 6.80

6.50 6.80 7.5 7.5

6.50 6.80 6.80 7.00

6.50 6.50 7.00 7.00

6.00 6.50 6.80 7.5

6.0vo 6.50 6.80 7.0cl

6.0vo 6.00 6.5cl 7.0cl

5.0vo 6.00 6.OcI 7.0cl

7.5 7.0 7.0 7.5

7.5 6.5d 7.0 7.5

6.5d 6.5d 6.5d 8.0

6.5d 6.5d 6.5d 8.0

6.5dy 7.0 6.Od 7.5

6.5dy 6.5dy 5.5d 7.0

6.Ody 6.Ody 5.5dy 6.0d

5.Ody 5.5dy 5.Ody 5.0d

Total bread scores generally followed loaf volume and crumb color trends. Remix bread scores (Figure 3) decreased at all salt levels with increasing fermentation times. With low salt levels, high bread scores were obtained with shorter fermentation times while with high salt levels, low bread scores were obtained at all fermentation times. With the Remix-to-peak method bread scores (Figure 4) showed the same decreasing trend with increasing fermentation time at lower salt levels. With 2.0010 salt, a similar trend was evident although decreases at longer fermentation times were not as evident. In contrast, with 3.0% salt increasing fermentation time initially led to large increases in bread score followed by a period of little change and a decrease at longer fermentation times. High bread scores were obtained with 0.5, 1.0 and 2.0% salt at shorter fermentation times (45-105 min) while high bread scores were obtained with 3.0% salt at intermediate fermentation times (105-195 min). The longer fermentation requirements of the latter for optimum baking response was probably related to the strengthening effect of the high salt as shown by the longer mixing requirements (Table 3). At shorter fermentation times,

the "mellowing" effect on the gluten proteins would be insufficient to overcome the overly-strong ("bucky") dough characteristics. Overall, loaf volume, internal and external bread characteristics and total bread scores showed less sensitivity to fermentation time compared to previous results obtained with traditional straight dough procedures (Clark, 1929; Harris, 1934; Freilich and Frey, 1939a; EI-Dash, 1978). These differences are probably related to the effects of remixing the dough after fermentation which reduces over-oxidation (excess bromate effect) and generally reduces the overall effects of over-fermentation (Freilich and Frey, 1939b; Irvine and McMullan, 1960). The effects of fermentation time and salt level upon bread characteristics was also studied at constant absorption (data not shown). With both the Remix and Remix-to-peak methods, bread scores tended to be lower at shorter and longer fermentation times at all salt levels compared to results obtained at optimum absorptions. The major factor contributing to these differences was the decrease in crumb structure values which were especially evident at longer fermentation times with 2.0 and 3.0% salt. Small reductions in loaf

80

...

60

o

40

~ ~

80

... 60

o'"

~ o 40

~

'"

'"

III

III

20

30

....

_- .......--..... 60

90

20

---.---....---------120

150

180

210

240

270

FERMENTATION TIME. min

Fig. 3 Effects of fermentation time and salt level on Remix total bread scores. Sodium chloride concentrations: 0.5070 = 0 - - 0 : I.O% = . - - . ; 2.0% = 0 - - 0 ; 3.0% = . - -•. 264 / Preston et al.

30

60

90

120

150

180

210

240

270

FERMENTATION TIME. min

Fig. 4 Effects of fermentation time and salt level on Remix-to-peak total bread scores. Sodium chloride concentrations: 0.5% = 0 - - 0 ; I.O% = . - - . ; 2.0% = 0 - - 0 ; 3.0% = . - -• . J. InSI. Can. Sci. Technol. Aliment. Vol. 17. No.4. 1984

volumes and loaf appearance also occurred with constant absorption at shorter and longer fermentation times.

Conclusion Where maximum requirements have been satisfied at the remixing stage as determined by the peak of the mixing curve (Figure 2), the various salt levels produced minimal differences in loaf volume in the fermentation time range from 135 to 162 min. With 0.5 to 3.0% salt, loaf volumes ranged from 885 to 810 cc respectively with the 2.0 and 3.0070 salt values being indistinguishable (approximately 810 cc). The 0.5 and 1.0% salt levels produced the higher volumes of 885 and 885 cc respectively. Therefore, at the Remix standard fermentation time of 165 min, the effect of salt level differences are minimized providing the mixing is satisfied. However, as fermentation time was reduced the effect of salt level became much more distinct in terms of loaf volume. In contrast, the standard fermentation time.produced widely differing loaf volumes (Figure 1) and bread scores for different levels of salt when a fixed remixing time was used. This illustrates the pronounced effect of salt level on mixing requirements in terms of the bread produced. Loaf volumes for 0.5, 1.0,2.0 and 3.0% salt were 865,855, and 485 cc respectively. Large differences in bread properties occurred across the full range of fermentation times for 1.0, 2.0 and 3.0% salt levels with only marginal differences between the 0.5 and 1.0% levels.

References Black, H.C., Preston, K.R. and Tipples, K.H. 1981. The GRL Pilot Mill. I. Flour yields and analytical properties of flour streams milled from Canadian red spring wheats. Can. Inst. Food Sci. Technol. J. 14:315. Bohn, L.J. and Bailey, C.H. 1937. Effect of fermentation, certain dough ingredients and proteases upon the physical properties of flour doughs. Cereal Chern. 14:335. Clark, R.J. 1929. Loaf volume as produced by different flours under prolonged fermentation. Cereal Chern. 6:338.

Can. Insi. Food Sci. Techno!. J. Vol. 17. No.4. 1984

Dexter, J.E., Matsuo, R.R., Preston K.R. and Kilborn, R.H. 1981. Comparison of gluten strength, mixing properties, baking quality and spaghetti quality of some Canadian durum and common wheats. Can. Inst. Food Sci. Technol. J. 14:108. EI-Dash, A.A. 1978. Standardized mixing and fermentation procedure for experimental baking test. Cereal Chern. 55:436. Fisher, M.H., Aitken, T.R. and Anderson, J.A. 1949. Effects of mixing, salt and consistency on extensograms. Cereal Chern. 26:81. Freilich, J. and Frey, C.N. 1939a. Dough oxidation and mixing studies. I. The action of potassium bromate in dough. Cereal Chern. 16:485. Freilich, J. and Frey, C.N. 1939b. Dough oxidation and mixing studies. II. Effects of remixing after fermentation. Cereal Chern. 16:495. Galal, A.M., Varriano-Marston, E. and Johnson, J.A. 1978. Rheological dough properties as affected by organic acids and salt. Cereal Chern. 55:683. Halton, P. 1961. Amylase activity, damaged starch and water absorption. Milling 136(6):146. Harris, R.H. 1934. The influence of malt, sucrose, and flour protein upon the fermentation tolerance of doughs treated with varying increments of potassium bromate. Cereal Chern. 1l:261. Hlynka, I. 1962. Influence of temperature, speed of mixing and salt on some rheological properties of dough in the farinograph. Cereal Chern. 39:286. Hoseney, R.C., Hsu, K.H. and Junge, R.C. 1979. A simple spread test to measure the rheological properties of fermenting dough. Cereal Chern. 56:141. Irvine, G.N. and McMullan, M.E. 1960. The "Remix" baking test. Cereal Chern. 37:603. Kilborn, R.H. and Tipples, K.H. 1981. Canadian test baking procedures. I. GRL Remix method and variations. Cereal Foods World 26:624. Orth, R.A. and Bushuk, W. 1972. A comparative study of wheats of diverse baking qualities. Cereal Chern. 49:268. Preston, K.R. and Tipples, K.H. 1980. Effects of acid-soluble gluten proteins on the rheological and baking properties of wheat flours. Cereal Chern. 57-314. Preston, K.R., Kilborn, R.H. and Black, H.C. 1982. The GRL Pilot Mill. II. Physical dough and baking properties of flour streams milled from Canadian red spring wheats. Can. Inst. Food Sci. Technol. J. 15:29. Tipples, K.H. 1969. The relation of starch damage to the baking performance of flour. Bakers Digest 43(6):28.

Accepted January 10, 1984

Preston et al. / 265