Your company is interested in developing a roasted soybean product to meet consu
ID: 301778 • Letter: Y
Question
Your company is interested in developing a roasted soybean product to meet consumers’ interest in nutritional snack foods. To optimize the quality of the roasted soybeans, the product development team has to make several decisions and has asked you for your input.
a. Sensory studies have determined that a L* value of 55 (HunterLab Colormeter; 100=white, 0=black) for the roasted soybeans is optimal. In a pilot run, the roasted soybeans had an L* value of 37. Discuss the reaction responsible for the color formation (include reactants and products). How would you suggest altering the processing to produce a product with optimal L* value?
b. The roasted soybeans have a total fat content of 20%. The fatty acid composition of 2 cultivars of soybeans is shown below.
Fatty Acid
Traditional
New
Palmitic
10.4
12.7
Stearic
4.2
8.9
Oleic
23.7
23.4
Linoleic
53.1
53.6
Linolenic
8.4
1.2
Which cultivar would you recommend to minimize off-flavor formation during the 6-month shelf-life? Discuss the reactions involved and why the cultivar you selected would result in the best flavor quality.
c. The first step in the processing of the roasted soybeans is to soak the soybeans overnight. The product development team has asked your recommendation on whether to use IA-1008, a traditional cultivar which contains the lipoxygenase enzyme, or IA-1008-LF, a new cultivar that does not contain the lipoxygenase enzyme. As part of your recommendation, discuss the reaction lipoxygenase catalyzes and whether it is a desirable reaction.
Fatty Acid
Traditional
New
Palmitic
10.4
12.7
Stearic
4.2
8.9
Oleic
23.7
23.4
Linoleic
53.1
53.6
Linolenic
8.4
1.2
Explanation / Answer
Five food-grade soybean cultivars were dry- and oil-roasted and stored for 6 months. The effects of cultivar, roasting, and storage on soybean composition were determined. Composition of roasted soynuts was measured on raw soybeans, roasted soynuts after roasting, and roasted soynuts after six months of storage. Moisture contents decreased after roasting and increased during storage. Oil-roasted soynuts were lower in moisture content than dry-roasted soynuts. Oil-roasted soynuts had significantly higher lipid contents than raw soybeans and dry-roasted soynuts due to the absorption of oil. Reductions were observed in reducing sugars and free amino acids with roasting. Greater reductions were seen in oil-roasted soynuts because of the higher roasting temperature and presumably increased Maillard browning. Storage resulted in minor changes in soluble sugars. Most free amino acid contents decreased during storage.
Effects of Roasting on Soybeans Effects of Roasting on Proteins Roasting causes beneficial nutritional changes to occur in soybeans. Anti-nutritional factors such as trypsin inhibitors and haemagglutinins are inactivated up to 95 and 100% respectively during roasting . In a study by Ramamani and others the protein efficiency ratio (PER) increased from a negative value for raw soybeans to 1.8 for roasted soybeans. Albino rats could not grow on a diet of raw soybeans as their source of protein. In addition to the desirable nutritional changes, desirable flavor compounds are also formed. However, roasting does decrease the availability of some essential amino acids, namely lysine, through Maillard browning. For optimal nutrition, the amount of heat treatment needed to inactivate most of the anti-nutritional factors must be balanced with the loss of essential amino acids (Ramamani and others 1996). Effects of Roasting on Lipids Effects of roasting soybean fatty acids vary with the temperature and length of roasting. Higher roasting temperatures (150 °C and 170 °C) tended to increase relative contents of saturated and monounsaturated fatty acids and decrease contents of polyunsaturated acids slightly compared to a roasting temperature of 130 °C (Jung and others 1997). Higher roasting temperature also appeared to increase the formation of conjugated dienes and trienes. However, higher roasting temperatures could also induce the formation of interfering substances that could be mistakenly be measured as oxidation products (Jung and others 1997). Isomerization can be induced by roasting, possibly leading to formation of trans fatty acids (Amaral and others 2006). In fact, roasting of hazelnuts caused a small increase in the amount of trans fatty acids as compared to the raw hazelnuts. (Amaral and others 2006). 12 Effects of Roasting on Carbohydrates While carbohydrates do not represent the largest or most important component of soybeans they do play an important role in the nutrition and the processing of soybeans. The oligosaccharides are most important nutritionally. As for the effects of processing on soybean carbohydrates, the reducing sugars are most affected. Storage conditions, such as humidity and temperature, and processing conditions can induce hydrolysis of sucrose, raffinose, and stachyose producing more reducing sugars (Locher and Bucheli 1998; Oosterveld and others 2003). The reducing sugars react with free amino acids and peptides during roasting via Maillard browning to create desirable roasted flavors (Ponquett 2002). During the roasting process of cocoa beans most of the fructose and all of the glucose were degraded. In this study there were no decreases in the non-reducing sugars sucrose, raffinose, stachyose, or verbascose (Redgwell and others 2003). Maillard Browning Maillard browning is the predominant type of non-enzymatic browning occurring in thermally-processed foods (Hwang and others 1995). Maillard browning and Strecker degradation are responsible for the formation of pleasant roasted flavor compounds and melanoidin formation (Martins and others 2001; Ponquett 2002). According to Basha and Young (1996), reducing sugars and amino acids are the major precursors of desirable flavor compounds in roasted peanuts. Maillard browning is initiated when a reducing sugar condenses with a free amino group, usually a free amino acid or amine side chain on a protein to form N-substituted glycosylamine. This reaction is favored during heating at higher pH’s. The glycosylamine rearranges to form an Amadori rearrangement product. The type of degradation of the Amadori product is dependent on the pH of the system. The degradation products formed are highly reactive and continue to degrade through a variety of reactions including dehydration, cyclization, retroaldolization, rearrangement, isomerization and further condensation 13 reactions. Eventually brown nitrogenous polymers and co-polymers, termed melanoidins, are formed. Within this degradation process, desirable flavor and aroma compounds are formed (Martins and others 2001). Roasted Flavor Compounds and Pyrazine Formation The compounds responsible for pleasing aromas and flavors in heat-treated foods are primarily heterocyclic compounds including furans, thiazoles, thiophenes, oxazoles, pyrroles, pyridines, and pyrazines (Hwang and others 1995). Pyrazines are the most abundant of the heterocyclic compounds formed during roasting and are responsible for toasted and roasted flavors and yellow color formation in cooked foods (Lee and Shibamoto 2002). There are three groups of pyrazines: alkylpyrazines, bicyclic pyrazines, and acetylpyrazines. Alkylpyrazines contribute significantly to the desirable flavor of heat-treated foods. Monosubstituted-pyrazines typically have nutty and/or roasted notes and higher alkylsubstituted pyrazines have fatty and/or waxy odors. Fried beef, roasted nuts, cocoa, and coffee aromas were identified with alkyl substituted dihydrocyclopentapyrazines (Hwang and others 1995). The quantity and quality of compounds produced in Maillard browning depends on the precursors, thermal processing parameters, pH, and quantitative ratio of amino nitrogen to reducing sugar (Martins and others 2001). According to Hwang and others (1995) bicyclic pyrazines require temperatures over 150°C for formation whereas monocyclic pyrazines form at around 120°C. Pyrazine formation in food systems is complex and more than one amino acid is present. To better understand the mechanisms of pyrazine formation, model systems consisting of individual amino acids and sugars have been studied extensively. Using a model system, Hwang and others (1995) found that most pyrazines are formed regardless of what amino acids are present, but some higher molecular weight pyrazines are only formed in the presence of certain amino acids. In an aqueous model system at pH 10, 4 amino acids were individually heated with glucose and the amounts of pyrazines were compared. 14 Arginine heated with glucose and lysine heated with glucose produced the greatest quantity of pyrazines. Histidine and glycine individually paired with glucose produced considerably smaller amounts (Huang and others 1989). Hwang and others (1995) investigated the effects of heating two amino acids together with glucose. Glycine was chosen as the amino acid that all the other amino acids would be reacted with. Its nitrogen was isotope-labeled and it was reacted with glutamine, glutamic acid, asparagine, lysine, arginine, phenylalanine, or isoleucine at pH 7. Glutamine and glutamic acid, when individually reacted with glycine, resulted in the lowest percentage yield of pyrazine formation and asparagine resulted in the highest percentage yield of pyrazine formation. Asparagine has been shown to have a faster deamination rate than glutamine, perhaps explaining the difference in pyrazine yield. Because the glycine was isotope-labeled it was determined that in a reaction mixture with lysine, glycine had the highest overall pyrazine yield compared to the other amino acids. In a reaction mixture with arginine, glycine had the lowest overall pyrazine yield compared to the other amino acids. Lysine appeared to be a synergist in increasing the reactivity of glycine whereas arginine acted like an inhibitor depressing pyrazine generation ability of other amino acids (Hwang and others 1995). Effect of Amino Acid Composition on Roasted Flavor Because the amino acids present in the reaction mixture influence the flavor compounds formed in food during roasting, differences in the free amino acids present in a soybean cultivar have the potential to influence flavor. Basha and Young (1996) stated that free amino acid contents in peanuts differ by variety, planting location, and maturation. Yanagisawa and others (1997) found that differences in free amino acid contents were cultivar specific between vegetable-type and grain-type cultivars of soybeans. Amino acids considered to be typical roasted flavor precursors in roasted peanuts include aspartic acid, glutamic acid, glutamine, asparagine, histidine, and phenylalanine. 15 Threonine, tyrosine, and lysine are considered to contribute to atypical flavor in roasted peanuts (Basha and Young 1996). Besides the flavors formed from free amino acids interacting with other compounds such as sugars and lipids during roasting, amino acids have their own flavor attributes. Alanine is highly correlated with sweetness and asparagine and glutamic acid are highly correlated with typical taste of edamame soybeans (Yanagisawa and others 1997). Roasting Temperature and Oxidative Stability Roasting temperature affects the color, pyrazine content, and oxidative stability of soybeans and the oil extracted from them. In a study by Jung and others (1997), soybeans were roasted at 130 °C, 150 °C, and 170 °C prior to oil extraction. Increased soybean roasting temperature resulted in the extracted oil being darker, redder, and more yellow. The pyrazine content of the oil increased greatly with increased roasting temperature. Nine alkylpyrazines were identified in the oil. Many of these alkylpyrazines have been previously identified in roasted soybeans (Wilkens and Lin 1970) and in roasted peanuts (Walradt and others 1971). Jung and others (1997) determined that 2,5-dimethylpyrazine was most responsible for the nut-like aroma of oil from roasted soybeans. Higher roasting temperatures greatly increased the oxidative stability of the oil because many of the Maillard reaction products also have antioxidant properties. Consequences of Roasting Not only does the Maillard browning reaction produce desirable flavors and colors, but roasting itself contributes to decreases in some of the volatile compounds associated with beany flavor, particularly aliphatic aldehydes and alcohols. Not all of the undesirable flavor compounds decrease upon roasting, however. N-hexanol, 1-octen-3-ol and n-hexanal were not significantly reduced during roasting of soybeans (Kato and others 1981). Kato and others (1981) concluded that the newly formed desirable volatile compounds were able to mask the beany flavor of the raw soybeans. 16 The consequences of Maillard browning are both positive and negative. Because proteins are involved in the reaction, a loss of essential amino acids such as lysine and tryptophan can occur, as well as decreased protein digestibility (Martins and others 2001). Formation of mutagens also occurs (Lee and Shibamoto 2002) although none of these compounds have been reported to correlate with human cancer (Martins and others 2001). The formation of these mutagens may be counteracted by the formation of mutagen inhibitors, termed desmutagens, in the Maillard reaction (Martins and others 2001). In addition to desmutagens, antioxidants are also formed in the Maillard reaction that have been shown to protect foods against lipid oxidation (Jung and others 1997; Lee and Shibamoto 2002; Martins and others 2001). Maillard browning is a very complex set of reactions that result in desirable colors, flavors, and antioxidants as well as some undesirable mutagens. The task is to balance the negative effects with the positive effects by controlling processing parameters. Soybean Lipids and Off-Flavor Generation The polyunsaturated fatty acids in soybeans make them and the products made from them prone to oxidative stability problems. Linolenic acid with three double bonds is considered to be the most problematic. The off-flavors due to the presence of linolenic acid have led to the development of low-linolenic acid soybean cultivars (Hui 1996). In the past, soybean oils were hydrogenated to improve the stability but with the concern about trans fats, the food industry is interested in the development of more stable soybeans oils that do not require hydrogenation. Flavor reversion is characteristic of oils containing linolenic acid and contributes to the off-flavors in soy products. Flavor reversion is described as “beany and grassy” at the beginning of oxidation and “fishy or painty” at more advanced stages of oxidation. This reversion develops at peroxide values of 10 or less and is mostly detected organoleptically (Hui 1996). Flavor reversion is often thought to be an oxidative process, but there is some 17 evidence that it is a non-oxidative process. Antioxidants are ineffective at hindering flavor reversion and hydrogenation is not completely effective in eliminating it, although hydrogenation is able to slow down rancidity (Hui 1996). Lipoxygenase, an enzyme believed to be a major initiator of peroxidation of lipids is present at approximately 2% of total seed protein in soybeans. Lipid peroxides are formed from the polyunsaturated fatty acids in soybeans, namely linoleic and linolenic acids. These peroxides can also be formed non-enzymatically by the attack of activated oxygen species (Dahuja and Madaan 2003). Lipid peroxides are then broken down further by enzymes such as hydroperoxide lyase or broken down non-enzymatically. This breakdown leads to the formation of off-flavors. The most predominant compounds responsible for off-flavors are medium chain, primarily six carbon, alkylaldehydes or alkenylaldehydes and others . Hexanal is produced by enzymatic oxidation and cleavage of linoleic acid and 2-hexenal and hexenol are produced from the enzymatic oxidation and cleavage of linolenic acid (Kobayashi and others . Many studies have demonstrated reduced off-flavor formation when lowlipoxygenase or lipoxygenase-free soybeans are used. In soymilk, yields of volatile compounds were greatly decreased when lipoxygenases were lacking (Kobayashi and others 1995). Torres-Penaranda and others (1998) found that soymilk made from lipoxygenase-free soybeans had less cooked beany aroma, cooked beany flavor, and astringency than soymilk made from the normal soybean cultivar. In addition, there were no differences in desirable soymilk attributes between the soymilk made from lipoxygenase-free and normal soybean cultivars (Torres-Penaranda and others 1998). In a study by Dahuja and Madaan (2003), two varieties of low-lipoxygenase soybeans had lower thiobarbituric acid and carbonyl values than normal soybeans also suggesting lipoxygenase’s role in producing off flavors. Soybean’s natural health benefits make it an excellent food to incorporate into the American diet. Soybeans have the potential to increase the nutrient density of the diet and 18 stave off diseases such as cardiovascular disease and cancer. Soynuts are advantageous as a soyfood because the entire bean with all its nutrients is consumed. Furthermore, the roasting process has the potential to overcome the off-flavors typically associated with soy by formation of desirable roasted and nutty flavors.
Five food-grade soybean cultivars were dry- and oil-roasted and stored for 6 months. The effects of cultivar, roasting, and storage on soybean composition were determined. Composition of roasted soynuts was measured on raw soybeans, roasted soynuts after roasting, and roasted soynuts after six months of storage. Moisture contents decreased after roasting and increased during storage. Oil-roasted soynuts were lower in moisture content than dry-roasted soynuts. Oil-roasted soynuts had significantly higher lipid contents than raw soybeans and dry-roasted soynuts due to the absorption of oil. Reductions were observed in reducing sugars and free amino acids with roasting. Greater reductions were seen in oil-roasted soynuts because of the higher roasting temperature and presumably increased Maillard browning. Storage resulted in minor changes in soluble sugars. Most free amino acid contents decreased during storag.
Understanding the composition of soybeans (Glycine max) is important to understanding the quality attributes of the processed product. The moisture content of the finished product will influence its the stability and quality. In the case of a roasted nut-like product such as soynuts, the water activity, a related measure, will affect texture of the final product (Lee and Resurreccion 2006). During the roasting process, sugars and free amino acids are important precursors to the formation of desirable roasted flavors (Oupadissakoon and Young 1984; Bett and Boylston 1992; Basha and Young 1996; Ponquett 2002). The quantity and quality of compounds produced in the Maillard browning reaction depends on the precursors, thermal processing parameters, pH, and quantitative ratio of amino nitrogen to reducing sugar (Martins and others 2001). Reducing sugars, primarily fructose and glu
ucose, in soybeans react with the free amino acids via Maillard browning to produce furans, thiazoles, thiophenes, oxazoles, pyrroles, pyridines, and pyrazines (Hwang and others 1995). Pyrazines are the most abundant of the heterocyclic compounds formed during roasting and are responsible for toasted and roasted flavors and yellow color formation in cooked foods (Lee and Shibamoto 2002). The oligosaccharides sucrose, raffinose, and stachyose are largely unreactive, but they can undergo hydrolysis to produce reducing sugars. The amino acids present have an influence on the pyrazines formed (Hwang and others 1995). Depending on the types of free amino acids available for reaction typical or atypical flavors can be created. Amino acids considered to be typical roasted flavor precursors in roasted peanuts include aspartic acid,
glutamic acid, glutamine, asparagine, histidine, and phenylalanine. Threonine, tyrosine, and lysine are considered to contribute to atypical flavor in roasted peanuts (Basha and Young 1996). Lipids, which constitute approximately 18% of soybeans by weight (American Soybean Association 2006), also influence the flavor of soy products. Linoleic acid is the 25 predominant fatty acid found in soybeans and makes up 54% of lipid fraction of soybeans. Soybeans also contain a relatively high amount of linolenic acid, 7% of the lipid fraction. Because of the high content of these two polyunsaturated fatty acids, soybean lipids are prone to oxidative stability problems. Linolenic acid with three double bonds, is the most problematic which has led to the development of low-linolenic acid soybean cultivars (Hui 1996). Soybeans also contain lipoxygenases which further exacerbate stability issues.
Lipoxygenases produce hydroperoxides from polyunsaturated fatty acids. These hydroperoxides breakdown either by enzymatic or non-enzymatic processes to produce volatile flavor compounds such as ketones, aldehydes, and alcohols. These compounds are responsible for the ‘beany’, ‘painty’, and ‘cardboardy’ off-flavors that discourage soy consumption by American consumers (Torres-Penaranda and others 1998). Soybean cultivars vary in their chemical composition. The most dramatic differences are demonstrated in soybeans developed to have specific traits. Some examples are cultivars developed to be high in protein, high in oil, low in linolenic acid, high in oleic acid, low in palmitic acid, or combinations of these characteristics. Composition is also affected by growing conditions. This includes the location, rainfall, and temperature, as well as other environmental parameters (Kumar and others 2006).
The raw composition of soybeans can impact the flavor stability and shelf-life of the final product. The processing impacts the composition of the soy product and vice versa. Shelf-life is very important because it is essential that the taste not only be acceptable after processing, but at the time of consumption. In the case of soynut processing roasting can cause an increase in stability of soybean flavor because many of the Maillard browning products produced from the sugars and amino acids have antioxidant properties. These antioxidants lend stability to the lipid fractions of the soybeans. Changes in soybean components do not occur independently of one another. Even though the Maillard browning reaction primarily involves reducing sugars and free amino acids, lipid oxidation products.
can also participate (Hidalgo and Zamora 2004). The interaction between the components in soybeans adds to the complexity of the roasting process. The objective of this study was to determine the effect of cultivar, roasting method, and storage on the chemical composition of roasted soynuts. Materials and Methods Soybean Cultivars Five food grade soybean cultivars, IA 2064, IA 1008 LF, IA 1008, Prairie Brand 299, and Asgrow 2247, were evaluated in this study. IA 2064, IA 1008 LF, and IA 1008 were obtained from the Committee for Agricultural Development at Iowa State University and were grown during the 2004 crop year. Prairie Brand 299 and Asgrow 2247 were obtained from Central Iowa Soy LLC (Jefferson, IA) and were grown during the 2005 crop year. IA 2064 is a low- linolenic acid cultivar. IA 1008 LF is a lipoxygenase-null cultivar derived from the IA 1008 cultivar.
Soybean Roasting Processing of each cultivar and roasting method (dry- or oil-roasted) was conducted in duplicate. The soybeans were soaked in water (3:1 wt/wt, water:soybeans) for 20-24 hours at 4°C prior to roasting. The dry-roasted soybeans were roasted in 2000 g (soaked weight) batches in a drum roaster (Gold Medal Funfood Equipment & Supplies, Cincinnati, OH, U.S.A.) for three hours. The roaster did not provide temperature control adjustments. After roasting, the soybeans were allowed to cool on paper towels. Oil-roasted soybeans were roasted in 500 g (soaked weight) batches in a deep-fat fryer (7.5 liter oil capacity; Star Mfg. International Inc., Smithville, TN, U.S.A.) at 177°C for 9 minutes and 10 seconds in vegetable oil (Crisco®, J.M. Smucker Co., Orrville, OH, U.S.A.). After roasting the soybeans were removed from the oil and the excess oil was allowed to drain back into the deep fat fryer for 30 seconds. The soybeans were then allowed to cool on paper towels.
Because the oil quality changes as the frying time increases, the order of roasting of the cultivars was randomized. For optimum flavor, the oil was heated 1½ hours prior to roasting the soybeans and the first batch roasted in the oil was discarded. The total amount of roasting time for all batches was short enough that it was not necessary to change the oil (White 2006). Samples from the fresh oil, the oil after 1½ hours of heating, the oil after 1½ hours of roasting, and the oil at the end of roasting time were collected. Peroxide value, aldehyde content and free fatty acid content were determined to ensure that the oil had not deteriorated excessively. The SfTest® System (SfTest®, Inc., Tempe, AZ, U.S.A.) was used to measure peroxide value, aldehyde content, and free fatty acid content of the oil samples taken during oil roasting. Preparation reagent (isopropyl alcohol) was added to the oil sample in a 10:1 ratio for the peroxide value determination. The oil was analyzed as is for the free fatty acid content and aldehyde content determination. The PeroxySafe™, AldeSafe™, and FASafe™ Kit-STD protocols were followed for each test. Peroxide values were expressed as meq peroxide/kg of sample. Aldehydes were expressed as µmol of malonaldehyde/kg sampl Free fatty acids were expressed as percent oleic acid in the sample.
Peroxide values are useful for initial oil quality measurements, but peroxides breakdown rapidly at elevated temperatures and should not be used to monitor oil processes such as frying (White 2000). Initial peroxide values for oil were 0.12 meq O2/kg sample or less. Oils with peroxide values of 1 meq O2/kg or less are considered to be unoxidized and of high quality (Gerde and others 2007). Aldehyde contents were less than 2.0 µmols/kg of sample initially and reached a maximum value of 29.3 µmols/kg of sample at the end of frying. Free fatty acid contents were less than 0.1% even by the end of frying indicating that the oil had not deteriorated markedly. Even fresh refined, bleached, and deodorized oils can contain up to 0.05% free fatty acids (Su and White 2004).
The dry- and oil-roasted soynuts were stored for up to 6 months in individual 7 oz Whirl-Pak bags (3 mil thickness, oxygen permeability 209.5 cc/100 sq in/24 hrs; moisture permeability 0.48 gms/100 sq in/24hrs, Nasco Fort Atkinson, WI, U.S.A) by month, roast, and cultivar. Each bag remained sealed until analyzed. The individual Whirl-Pak bags for each month were stored inside Ziploc® gallon storage bags (S.C. Johnson & Son Inc. Racine, WI, U.S.A.) which were stored in a cupboard to minimize exposure to light. Total storage time of the study was 6 months. Suboptimal packaging was used so that if storage had an effect, it would be demonstrated during the 6 months of storage.
Chemical Analyses
Soybeans were frozen at -18°C overnight and then ground using a Magic Mill III Plus High Speed Flour Mill (Magic Mill, Upper Saddle River, NJ, U.S.A.) on the coarsest setting. The grinding process produces a considerable amount of heat. Freezing the beans prior to grinding minimizes any heat-related reactions that can affect composition. Ground soybeans were used for all chemical analyses.
Moisture Content
Duplicate samples of ground beans (4 g) were dried in an oven at 105°C to a constant weight (AOAC 1984).
Lipid and Fatty Acid Content
Lipids were extracted from the soybeans using a modified Bligh and Dyer method (Lin and others 1995). Duplicate samples of ground beans (5 g) were extracted in 75 ml of CHCl3:CH3OH (2:1 vol/vol) for one hour with stirring. The samples were then filtered using a Buchner funnel with a No. 1 Whatman paper (Whatman International Ltd, Maidstone, England). The filtrate was washed with 5 ml aliquots of CHCl3:CH3OH. Twenty milliliters of water (equal to 20% of total volume) was added to the filtered sample. The samples were centrifuged (Beckman Coulter, Inc. Model J2-21; Fullerton, CA, U.S.A.) for 15 minutes at 1000 x g. The methanol layer was removed by aspiration. The chloroform layer was poured through sodium sulfate
Soybean Cultivars Five food grade soybean cultivars, IA 2064, IA 1008 LF, IA 1008, Prairie Brand 299, and Asgrow 2247, were evaluated in this study. IA 2064, IA 1008 LF, and IA 1008 were obtained from the Committee for Agricultural Development at Iowa State University and were grown during the 2004 crop year. Prairie Brand 299 and Asgrow 2247 were obtained from Central Iowa Soy LLC (Jefferson, IA) and were grown during the 2005 crop year. IA 2064 is a low-linolenic acid cultivar. IA 1008 LF is a lipoxygenase-null cultivar derived from the IA 1008 cultivar. Soybean Roasting Processing of each cultivar and roasting method (dry- or oil-roasted) was conducted in duplicate. The soybeans were soaked in water (3:1 wt/wt, water:soybeans) for 20-24 hours at 4°C prior to roasting. The dry-roasted soybeans were roasted in 2000 g (soaked weight) batches in a drum roaster (Gold Medal Funfood Equipment & Supplies, Cincinnati, OH, U.S.A.) for three hours. The roaster did not provide temperature control adjustments. After roasting, the soybeans were allowed to cool on paper towels. Oil-roasted soybeans were roasted in 500 g (soaked weight) batches in a deep-fat fryer (7.5 liter oil capacity; Star Mfg. International Inc., Smithville, TN, U.S.A.) at 177°C for 9 minutes and 10 seconds in vegetable oil (Crisco®, J.M. Smucker Co., Orrville,
B.The New cultivar is better suitable
C.The IA-1008-LF, is better to produce cultivar.
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