Abstract
Wheat flour was gradually replaced with defatted rice bran (DRB) at different levels. Five treatments (T0 = control i.e. without DRB; T5 = 5% DRB; T10 = 10% DRB; T15 = 15% DRB; T20 = 20% DRB) were used for bread preparation. Bread loaves were analyzed for chemical composition and sensory evaluation at different storage intervals i.e. S0, S24, S48, S72, S96, and S120 hours. Protein, ash, fiber, and mineral contents of breads were improved and moisture decreased significantly, whereas fat content showed non-significant effect for increasing levels of defatted rice bran. Maximum protein, ash, fiber, K, Ca, and Mg contents were found in T20 while minimum values were observed in T0. Moisture and Na contents were decreased by the subsequent addition of rice bran. Treatment T5 got maximum scores for external characteristics (volume, color of crust, symmetry of form, evenness of bake, character of crust) and internal characteristics (grain, color of crumb, aroma, taste, and texture) of pan bread. From chemical assay and sensory evaluations, the authors concluded that the quality bread can be improved by the addition of 5% DRB having high fiber and mineral content for commercialization.
INTRODUCTION
Rice (Oryza sativa) is ranked second cereal crop being produced in Pakistan. During 2005–2006, total production of rice was 5547 thousand tonnes. Estimated bran yield from this production was about 443 thousand tonnes.[Citation1] Rice bran, as a co-product of the rice milling industry, is yet not to be efficiently utilized for human consumption. In spite of its excellent nutrition, its hypoallergenicity, and recently claimed nutraceutical properties, rice bran is mainly utilized for animal feed or fuel purposes. It is of interest to incorporate this healthy ingredient back into our diet.[Citation2] Rice bran, a good source of protein and fat, is at present underutilized as a food material. The potential of producing rice bran at the global level is 27.3 million tonnes.[Citation3] Due to its over all composition, nutritional profile, functional characteristics, and apparent hypoallergenicity, rice bran has many applications in a diet which is characterized by high in dietary fiber and low in saturated fat. It may be particularly beneficial to those individuals who show allergenecity to other cereal grains. However strong evidences are available that the consumption of rice bran may be beneficial in reducing the risk of cardiovascular disease and colon cancer.[Citation4] Defatted rice bran increases dough yield, contributes to an attractive tan crumb and crust, does not disturb fermentation or mixing tolerance of dough, causes baked products to remain fresher and more moist and adds significant amino acids, minerals and vitamins to baked goods.[Citation5]
Rice bran can be substituted successfully up to 15% replacement level without affecting loaf weight, height or volume of bread.[Citation6] Rice bran, stabilized by dry heat and extrusion cooking, can be substituted with wheat flour at levels 5 to 20% in breads and cookies. However wheat flour replacement increased baking absorption, decreased loaf volume and overall quality scores of bread. Addition of rice bran to wheat flour increased the contents of proteins, lysine and dietary fiber in bread and cookies proportionately to the level of substitution.[Citation7] Stabilized full fat rice bran up to 20% level and unstabilized full fat or stabilized defatted rice bran up to 10% was found suitable in various food products.[Citation8] Present study was conducted to prepare fiber and mineral enriched pan bread by using defatted rice bran. Chemical characteristics and sensory attributes were also studied to find out the most appropriate level of defatted rice bran addition in bread without affecting its internal and external characteristics for commercialization purposes.
MATERIALS AND METHODS
Procurement and Preparation of Rice Bran
Rice bran (RB) of Basmati Super was collected from Reem Rice Mills, Sheikhupura (Pakistan). It was stabilized by heating at 125–135°C for 1 to 3 seconds to inactivate enzyme activity to minimize rate of FFA production and rancidity.[Citation9] After stabilization, RB was treated with hexane to remove fat/germ portion. Defatted rice bran (DRB) was steamed for 5 to 10 minutes at 93–104°C to inactivate residual lipase activity.[Citation10]
Proximate Assay
Defatted rice bran was analyzed for moisture, crude protein, crude fat, crude fiber, total ash, and NFE according to respective methods as described by AACC.[Citation11]
Estimation of Minerals
Defatted rice bran was also analyzed for Na, K, Ca, and Mg following the standard method as described by AOAC.[Citation12] A 0.5 g sample was digested in kjeldahl's flask with 10 mL conc. HNO3 (70%). The sample was heated at 60°C for 15 minutes to get clear solution. Then 5 mL 60% perchloric acid was added and heated at 80°C for 20–30 minutes. Samples were strongly heated at 400–500°C for one hour, untill volume reduced to 1–2 mL. These samples were diluted to 100 mL by the addition of distilled water. Na and K were measured by Flame photometer while Ca and Mg were analyzed by atomic absorption spectrophotometer. Standard solutions of different concentrations were used before running the samples, like KCl and NaCl were used for determination of Na and K.
Preparation of Pan Bread
The bread was prepared by straight dough method with some modification in AACC procedure. Defatted rice bran was incorporated in the dough during mixing at different levels as mentioned in .
Table 1 Treatments used in the study.
Chemical Analysis of Bread
Bread loaves were analyzed for moisture, crude fat, crude fiber, crude protein, total ash, and nitrogen free extract (NFE) as described in AACC.[Citation11]
Estimation of Minerals in Bread
Bread samples were also analyzed for Na, K, Ca and Mg content following the standard method as mentioned in AOAC.[Citation12]
Sensory Evaluation
Sensory evaluation of bread samples prepared from different DRB levels was carried out for the external characteristics, i.e., volume, color of crust, symmetry of form, evenness of bake, character of crust, and internal characteristics like grain, color of crumb, aroma, taste, and texture at 0, 24, 48, 72, 96, and 120 hours of storage (Appendix A). Scoring was completed according to the experimental bread score report of American Institute of Baking using trained taste panel.[Citation13]
Statistical Analysis
The data obtained for each parameter was statistically analyzed by using Analysis of Variance technique (ANOVA) and treatment means were compared by using Duncan's Multiple Range Test.[Citation14]
RESULTS AND DISCUSSION
Chemical Assay of Defatted Rice Bran
Defatted rice bran obtained after hexane extraction was chemically analyzed (). The analysis showed that defatted rice bran contained moisture, crude protein, crude fat, crude fiber, ash, and nitrogen free extract as 7.6%, 18.97%, 0.89%, 10.73%, 10.66%, and 51.15%, respectively. Mineral assay showed that defatted rice bran contained Na (7.5 mg), K (1280 mg), Ca (530 mg), and Mg (953 mg) per 100 g. The values obtained in the study are in close agreement to that reported by Saunders[Citation15] who analyzed, stabilized, parboiled, and defatted rice brans for proximate composition and mineral contents. Numerous studies conducted on various aspects of rice bran showed that it contains 13.2–17.3% protein, crude fat 0.6%, crude fiber 9.5–13.2%, and 9.2–12.2% total ash on dry weight basis.[Citation16,Citation17,Citation18,Citation19]
Table 2 Chemical assay of defatted rice bran.
Chemical Analysis of Bread
Supplementation of defatted rice bran has significant effect on moisture, crude protein, crude fiber, ash, nitrogen free extract (NFE), and mineral contents of bread whereas non-significant effect was observed for storage except moisture contents, which were varied for different time intervals. Interaction between treatment and storage did not exhibit significant difference ().
Table 3 Analysis of variance for chemical properties of defatted rice bread.
Highest moisture content (35 %) were found in T20 followed by T15 (34 %) and minimum were found in T10 (32.51%) containing 10% bran (). As bran contains more cellulose and other non starch polysaccharides that hold water up to several times of their weight. So with the increase of DRB level there was an increase in moisture content of bread; this is the reason T20, with the highest bran level, i.e., 20%, had maximum moisture content. Protein content is affected greatly due to different levels of rice bran. The highest protein content (9.39%) was found for T20 followed by 9.01, 8.31, 7.80, and 7.41 percent for T15, T10, T5, and T0, respectively. A more pronounced effect on protein content may be ascribed to the high protein content (18.97%) of DRB than that of wheat flour. With the increase in bran portion protein content of bread was also increased accordingly. Mean values for crude fat were 1.63, 1.54, 1.62, 1.62, and 1.66% for T0, T5, T10, T15, and T20, respectively. The non-significant differences, due to different treatments on fat content, are attributable to the fact that the rice bran was defatted before using in the bread loaves. Results pertaining to fiber contents showed that highest fiber content (3%) was established for T20 followed by 2.51, 2.00, 1.61, and 1.43% for T15, T10, T5, and T0, respectively. The lowest fiber content was observed in case of control (0.99%). As rice bran contains higher amount of crude fiber, i.e. 10.73% (), than the wheat flour, so subsequent addition of DRB progressively increased the fiber content of bread. Because bran is a good source of dietary fiber, such product types are attractive for hypercholesterolemic and hyperglycemic individuals. Mean values showed that the highest ash content 2.53% for T20 followed by 2.12, 1.67, 1.10, and 0.99 percent for T15, T10, T5, and T0, respectively. Ash contents were improved gradually from T0 to T20 by the level of substitution of DRB. Rice bran is plentiful in crude fiber and generally minerals are concentrated in fiber portion of grain. There is positive correlation between fiber and ash, therefore, the ash content of bread increased with increase in bran fortification level. NFE was found 88.55, 87.86, 86.40, 84.73, and 83.41 percent for T0, T5, T10, T15, and T20, respectively. The highest value (88.55%) was found in T0 (100% wheat flour), while the lowest (83.41%) was in case of T20. Due to the higher levels of protein, fiber, and ash contents rice bran has lower NFE content. It is obvious from the results that by increasing rice bran in the recipe there is declining trend in NFE content. Highest Na content (400.83 mg/100 g) was found for T0 followed by 381.46, 362.96, 340.31, and 324.15 mg/100 g for T5, T10, T15, and T20, respectively. The lowest Na content was observed in case of T20. Na content was decreased by increasing level of rice bran because rice is a unique cereal with negligible amount of Na. Mean values showed that highest K content was found to be 274.82 mg/100 g for T20 followed by 233.40, 182.86, 134.13, and 85.00 mg/100 g for T15, T10, T5, and T0, respectively. The lowest K content was observed for T0. Potassium content was increased significantly by increasing the level of rice bran. It is obvious from chemical assay of DRB () that it is a very good source of K, i.e., 1280 mg/100 g. So the supplementation of DRB in bread improved its mineral contents. Highest calcium content (178.88 mg/100 g) was found for T20 followed by 162.25, 143.86, 122.58, and 106.16 mg/100 g for T15, T20, T5, and T0, respectively. More pronounced increase for Ca content in case of T20 (162.25 mg/100 g) may be attributed to the higher Ca content of the rice bran, as the minerals are concentrated in the bran portion of grains. Results expressed that highest Mg content (194.30 mg/100 g) was found for T20 followed by 130.22, 93.54, 54.13, and 18.77 mg/ 100 g for T15, T10, T5, and T0, respectively. The lowest Mg content was observed in case of T0. Mg content was increased by increasing level of rice bran. Juliano and Bechtel[Citation20] also studied the composition of rice bran including mineral contents and observed that Ca, Mg, and K contents at 14% moisture level were present within the range of 30–120, 500–1300, and 10–200 mg/100 g of bran. Furthermore, Juliano and Bechtel considered Na in the category of minor ingredients and observed its negligible amount, i.e., 71–335 μg/g of rice bran. Fresh bread loaves (S0) contained maximum moisture percentage followed by the moisture percentage at S24, S48, S72, S96, and S120 hours of storage (). Because there is migration of moisture from crumb interior to the crust and then to the surrounding environment, the moisture content of the breads were lower after 120 hours (S120) of storage, as compared to fresh loaves. All other parameters of proximate assay, except moisture, including minerals showed non-significant differences due to storage.
Table 4 Effect of different treatments on chemical parameters of defatted rice bread.
Table 5 Effect of storage on chemical parameters of defatted rice bread.
Sensory Evaluation of Bread
Results pertaining to sensory attributes of bread () revealed highly significant effect of different treatments and storage intervals on sensory attributes like volume, color of crust, symmetry of form, evenness of bake, character of crust, aroma, grain, color of crumb, taste, and texture of bread.
Table 6 Analysis of variance for sensory properties of defatted rice bread.
Volume is the space occupied by the loaf of bread. The overall concept of loaf volume includes loaf shape, i.e., loaf height, length, and width, which should be in pleasing proportions to one another. Highest quality score for volume of bread () was obtained by T0 (6.26) followed by 5.97, 5.76, and 5.20 for T5, T10, and T15, respectively. T20 got the lowest scores (4.80). With the increase in rice bran level there is concomitant decrease in gluten protein of the flour because bran can hold more water so less moisture available for proper gluten development. Gluten plays a vital role in the retention of gas produced during fermentation. Therefore by increasing bran portion there was decreased gas retention resulting in lowered bread volume as obvious from results.
Table 7 Effect of different treatments on sensory attributes of defatted rice bread.
Crust color normally ranges from a deep golden brown of the top crust to the light golden brown of the side and bottom crusts. Crust color is markedly affected by baking temperatures, and the level of residual sugars present in the dough. Maximum score for color of crust (5.86) was obtained by T5 followed by 5.47, 5.13, 4.66, and 4.10 for T0, T10, T15, and T20, respectively. T20 got the lowest scores (4.10). Too much bran tends to cause the final bread to be darker; at low levels, however, as in case of 5% DRB, it may improve the pale color without requiring too much time or temperature. The results are in line with the previous findings of Lynn[Citation5] that defatted rice bran can contribute to attractive crust and crumb formation.
Symmetry of form, aside from that imparted by rigid pan dimensions, is indicative of a controlled final proof and a good, bold oven spring. The loaf should have a well-rounded top and be free of protruding sides and ends and sharp corners. T5 obtained maximum scores (3.33) for symmetry of form followed by 2.83, 2.50, 2.23, and 1.2 for T0, T10, T15, and T20, respectively. Slightly low levels of rice bran may strengthen dough to get a more symmetrical form and withstand oven spring and avoid collapse.
Evenness of baking is of obvious importance to bread quality. Heavy top crusts in association with weak sidewalls and bottom crusts, or the reverse, indicate improper oven heat distribution. Breads with these defects are generally unacceptable to the consumer. The ideal loaf will possess an over-all crust of quite uniform thickness, and a color that does not vary over an excessive range. T5 obtained maximum scores (2.48) for evenness of bake followed by T0 (2.23). Treatment T20 got the lowest scores (1.22). Evenness of baking is mainly affected by the baking temperature/time. However, low levels also improved this characteristic because small amounts of bran easily distributed throughout the dough, resulting in even moisture distribution and more even baking, rather than the other treatments containing more DRB ().
Generally consumers show a decided preference for a thin, tender crust in the conventional white pan loaf, whereas in hearth-type loaves, a thicker and crispy crust is characteristically considered a desirable quality attribute. The general practice of bread wrapping or packaging, while protecting the loaf against rapid moisture loss and thereby extending its shelf life, brings about a pronounced change in crust character within a relatively brief time by converting its short and tender texture to a more tough and leathery mouthfeel. T1 obtained maximum scores (2.26) for character of crust followed by 1.97, 1.82, 1.45, and 1.18 for T0, T10, T15, and T20, respectively (). At higher bran levels, crust tends to be too hard, hence unacceptable for the consumers. While bran at 5% level provided slight toughness to the crust with proper color development this slight hardness improved the bite of slice as well as the chewing ability.
Aroma is the quality perceived by the sense of smell. It plays a primary role mining consumer appeal. Depending on consumer preferences within this area, the aroma should incorporate wheaty, nutty, malty, and sweet diacetyl notes, and avoid acidic, musty, ropy, or rancid elements. Mean values showed that T5 obtained maximum scores (5.91) for aroma followed by 5.53, 5.18, 4.61, and 3.83 for T10, T5, T15, and T20, respectively. Presence of too much bran in bread may alter its aroma to become more branny than wheaty. However, bran at low levels may improve aroma of the bread as in case of T5. In the present study, stabilized rice bran was used with the reason that it will not impart rancid aroma and flavor to the end product.
Grain of the crumb has been defined “the cell structure as it is exposed when the loaf of bread is sliced.” A grain is designated as “open” if it consists of rather large individual cells, and as “close” if it consists of minute cells. A bread slice may have a uniformly open or uniformly close grain, or a range of variously-sized cells. T5 obtained highest scores (11.16) for grain followed by 10.63, 9.73, 8.56, and 7.76 for T0, T10, T15, and T20, respectively Rice bran at higher levels adversely affects grains of crumb resulting in thick walled coarse grained crumb structure due to poor gluten development during mixing owing to too much bran supplementation. However, in T5, supplementation of DRB is only 5% that gives better mixing stability resulting in strengthening of dough for better crumb or grain structure.
Crumb color is the end result of the contributions of all ingredients used in the bread formula. Flour color, in turn, is influenced principally by its relative freedom from bran particles and is thus, in large measure, an index of flour grade and milling efficiency. Hence, a loaf of bread made from a patent flour will normally have a brighter crumb color than one made from a straight flour. It is also influenced by the fineness and uniformity of the crumb's grain. Mean values showed highest scores (6.63) for T5 regarding color of crumb followed by 6.20, 5.56, 4.7, and 4.28 for T0, T10, T15, and T20, respectively. Lowest scores for color of crumb of bread were found for T20 because breads with more bran content are coarse grained and tend to be darker than those without bran or with very low levels of DRB.[Citation21]
Taste constitutes the second major component of flavor detected by the taste buds of the tongue and mouth membranes primarily as sour, salty, sweet, and bitter sensations. In practice, the consumer does not distinguish consciously between aroma, but reacts subjectively to their combined effect of flavor. Fresh bread typically has a slightly sweet-sour taste with a very light salty note, and a barely perceptible bitter element derived from the crust. Part of the perceived taste sensation is modified by the tactile character of the bread, designated as its eating quality or chewing quality. Taste is an important parameter in sensory evaluation. Bread prepared with 5% DRB (T5) obtained highest scores (14.26) regarding the taste of bread i.e. followed by 13.36, 11.97, 9.76, and 8.40 for T0, T10, T15, and T20, respectively (). At lower concentrations 5% bran improve the taste of bread without too much change in its typical flavor instead it added a mild branny taste appealing for consumers.
Texture of the loaf crumb is a major quality factor—with most consumers preferring a soft, resilient and short crumb, as they associate these attributes with product freshness. Texture manifests itself entirely through the sense of touch, i.e., how the crumb feels to the touch or what its mouthfeel is. T5 obtained highest scores (9.86) regarding the texture of bread followed by 9.13, 8.40, 7.46, and 6.76 for T0, T10, T15, and T20, respectively. T20 was awarded the lowest scores (6.76) for texture of bread. At higher concentrations, rice bran tends the texture of bread to be too hard—unacceptable for consumers. However at lower levels (5%) it strengthened grains of the crumb without much toughening and resulted in soft and resilient crumb (). The present results are supported by the previous findings that increasing level of bran particles in formulations had significant effect on both internal as well external attributes of bread consequently lowering its overall acceptability.[Citation22]
During our storage study (), the volume of bread decreased gradually from 7.12 (S0) to 3.72 (S120). A decrease in volume may be attributed to the loss of moisture resulting deleterious effects on crumb grain and ultimately on volume. Color of fresh bread loaves (S0) was 6.12, which decreased to 4.00 after S120. Symmetry of bread also exhibited significant effect due to storage and decreased from 2.92 (S0) to 1.84 (S120). Evaporation and gas loss from bread surface has inverse correlation with symmetry of bread showing declining trend towards acceptability. Fresh bread loaves (S0) obtained highest (2.28) score followed by 2.0, 1.8, 1.66, 1.42, and 1.26 for S24, S48, S72, S96, and S120 hours of storage for crust of bread. With an increase in storage time, water movement from crumb to crust causes the crust to become leathery rather than soft and smooth. Fresh bread (S0) has highest aroma (6.92) followed by 6.44, 5.56, 4.68, 3.76, and 2.74 for S24, S48, S72, S96, and S120 hours. There is loss of aromatic compounds from bread with the passage of time that affects the aroma and ultimately the consumer acceptability. Bread loaves gained the highest scores (11.2) for grains at S0 followed by 10.68, 10.08, 9.48, 8.52, and 7.48 for S24, S48, S72, S96, and S120 hours of storage. Starch retrogradation phenomena accelerated with the passage of time, leading to recrystallization of starch particles that collapsed the grain and directed towards deceasing trend for this parameter. Storage showed a momentous effect on color, i.e., 7.26 at S0 to 3.60 after S120 hours of storage. Fresh bread loaves (S0) obtained the highest scores (15.16) for taste followed by 13.28, 11.96, 10.84, 9.64, and 8.44 at S24, S48, S72, S96, and S120 hours of storage (). Flavoring compounds formed in bread, especially during fermentation are volatile in nature. When bread is stored for longer periods, the loss of these volatile compounds adversely affects the taste and overall appeal. Scores for taste of bread gradually decreased with the passage of time due to chemical and biochemical changes taking place in bread. The texture of bread significantly decreased from 11.00 at S0 hours to 9.56, 8.68, 7.72, 6.88, and 6.12 after S24, S48, S72, S96, and S120 hours of storage. Starch retrogradation causes crumb firmness. After the first day, amylose retrogradation causes the crumb structure to establish. After that, amylopectin retrogradation is the main reason for bread firming, and badly affecting its texture. Bread heating may cause the bread to retain its freshness as the energy applied may serve to break the bonds between starch polymers formed during retrogradation.[Citation23]
Table 8 Effect of storage on sensory attributes of defatted rice bread.
CONCLUSIONS
Defatted rice bran has great potential to be utilized for various bakery products without affecting the nutritional composition and sensory attributes. Overall quality and nutritional profile of pan bread was improved by DRB addition in various proportions. However, fiber and mineral enriched pan bread, with excellent quality, can be prepared by replacing the wheat flour with defatted rice bran up to 5% level without affecting internal and external characteristics of bread.
REFERENCES
- Government of Pakistan . 2006 . Economic Survey , Islamabad : G.O.P., Economic Affairs Division .
- Lima , I. , Guraya , H. and Champagne , E. 2002 . The functional effectiveness of reprocessed rice bran as an ingredient in bakery products . Nahrung , 46 : 112 – 117 .
- Prakash , J. 1996 . Rice bran proteins: properties and food uses . Crit. Rev. Food Sci. Nutr , 36 : 537 – 552 .
- Marshall , W.E. and James , I.W. 1994 . Rice Science and Technology , 1 – 15 . New York : Marcel Dekker Inc. .
- Lynn , L. 1969 . “ Edible rice bran foods ” . In Protein Enriched Cereal Foods for Word Needs , Edited by: Milner , M. 154 – 172 . St. Paul, MN : American Association of Cereal Chemists, Inc .
- Sharp , C.Q. and Kitchen , K.J. 1990 . Using rice bran in yeast bread in a home baker . Cereal Foods World , 35 : 1021
- Sharma , H.R. and Chauhan , G.S. 2002 . Effect of stabilized rice bran-fenugreek blends on the quality of breads and cookies . J. Food Sci. Nutr , 39 : 225 – 233 .
- Singh , B. , Sekhon , K.S. and Singh , N. 1995 . Suitability of full fat and defatted rice brain obtained from indian rice for use in food products . Plant Foods Hum. Nutr , 47 : 191 – 200 .
- Randall , J.M. , Sayre , R.N. , Schultz , W.G. , Fong , R.Y. , Mossman , A.P. , Tribelhorn , R.E. and Saunders , R.M. 1985 . Rice bran stabilization by extrusion cooking for extraction of vegetable oil . J. Food Sci , 50 : 361 – 368 .
- Yokochi , K. . Rice bran processing for production of rice bran oil and characteristics and uses of oil and deoiled bran . Proceedings of Rice By-products Utilization, International Conference . Edited by: Barber and Tortosa . Vol. III , Valencia, , Spain : Inst. Agroquim Technol. Aliments . Rice bran utilization: oil Valencia, Spain
- American Association of Cereal Chemists, Inc. 2000 . Approved methods of american association of cereal chemists , St. Paul, MN : AACC .
- Association of Official and Analytical Chemists . 1990 . Official methods of analysis , 15th , Arlington, VA : AOAC .
- Matz , S.A. 1972 . Bakery technology and engineering , CT : The AVI Publishing Company Westport .
- Steel , R.G.D. , Torrie , J.H. and Dickey , D. 1997 . Principles and procedures of statistics. A biometrical approach , 3rd , New York : McGraw Hill Book Company Inc. .
- Saunders , R.M. 1990 . The properties of rice bran as a foodstuff . Cereal Foods World , 35 : 632
- Houston , D.F. and Kohler , G.O. 1970 . Nutritional properties of rice , Washington, D.C : National. Academy of Sciences .
- Anonymous . 1977 . Seminar on edible bran rice , Vol. S25 , 106 Bombay : The Association of Solvent Extractors' .
- Pomeranz , Y. and Oryl , R.L. 1982 . “ Rice processing and utilization ” . In CRC Handbook of Processing and Utilization in Agriculture , Vol. II , West Palm Beach, FL : CRC Press .
- Holland , B. , Welch , A.A. , Unwin , I.D. , Buss , D.H. , Paul , A.A. and Southgate , D.A.T. 1991 . McCane and widdowson's the composition of foods , 5th , Cambridge : Royal Society of Chemistry, and MAFF .
- Juliano , B.O. and Bechtel , D.B. 1985 . “ The rice grain and its gross composition ” . In Rice chemistry and technology , Edited by: Juliano , B.O. 43 – 44 . St. Paul, MN : American Association of Cereal Chemists, Inc. .
- Sharma , H.R. , Chauhan , G.S. and Agrawal , K. 2004 . Physico-chemical characteristics of rice bran processed by dry heating and extrusion cooking . Int. J. Food Properties , 7 ( 3 ) : 603 – 614 .
- Gujral , H.S. , Mehta , S. , Samra , I.S. and Goyal , P. 2003 . Effect of wheat bran, coarse wheat flour, and rice Flour on the instrumental texture of cookies . Int. J. Food Properties , 6 ( 2 ) : 329 – 340 .
- Pyler , E.J. 1988 . “ Keeping properties of bread ” . In Baking science and technology , 3rd , Edited by: Pyler , E.J . Vol. II , 815 – 849 . Kansas : Sosland Publishing Co .