Effect of Infrared Baking on Wheat Flour Tortilla Characteristics     

F. Martínez-Bustos  S. E. Morales  Y. K. Chang  A. Herrera-Gmez  M. J. L. Martínez  L. Baos  M. E. Rodríguez  M. H. E. Flores 《Cereal Chemistry》1999,76(4):491-495

A new and improved method for baking wheat flour tortillas was evaluated. The method was faster and reduced tortilla dehydration. The aim of the study was to evaluate the efficiency of the infrared baking method on rollability, puffing, layering, color (lightness), and texture (cutting force and tensile strength) characteristics of wheat tortillas formulated and formed by the traditional (hand-rolled) and commercial (hot-press) methods. These tortillas were also compared with traditional tortillas cooked on a hot griddle and commercial tortillas cooked in a three-tier, gas-fired oven. In the infrared radiation (IR) method, tortillas were baked for 17 or 19 sec by IR using black-body radiation at a selected wavelength band and emission temperatures of 549 or 584°C. IR-baked tortillas showed good characteristics of rollability, puffing, layering, color, and texture. The loss of moisture during baking of the tortillas formed by hot-pressing and baked by IR was significantly lower than that of tortillas baked by traditional and commercial methods. X-ray diffraction of tortillas prepared by the traditional process and baked by the IR method showed a pattern similar to that of homemade tortillas baked on a hot griddle. The average energy used by the IR oven was less than that used in the commercial method which, in turn, is more efficient than the traditional hot griddle method.  相似文献   

Determination of Bran Contamination in Wheat Flours Using Ash Content,Color, and Bran Speck Counts     

Y. S. Kim  R. A. Flores 《Cereal Chemistry》1999,76(6):957-961

A fast new method based on image analysis, ScanPro Speck Expert (SPX), to determine the bran contamination in wheat flour was studied and compared with existing methods (air-oven, ash, and color measurements) using an Agtron color meter and a Minolta chromameter. Twenty-one hard red winter wheat flour samples with ash contents of 0.30–0.58% were collected from the Kansas State University pilot mill and used for this study. Intrinsic variability in the flour sample because of randomness of bran speck orientation and distribution in the sample holder could result in variation in the speck count. Simple and multiple linear regression analyses showed that estimation of flour ash content from the SPX results (R² = 0.91) would be more accurate than the results from color measurements (R² = 0.66 [Agtron color meter] and 0.74 [L*]). The added capability of SPX image analyzer to not only count the number of bran specks but also to measure their areas probably increases the accuracy of determining the bran contamination in wheat flour by image processing.  相似文献   

In vivo and in vitro protein digestibility and growth performance of animal and no‐conventional plant ingredients for river prawn Macrobrachium americanum (Caridea: Palaemonidae)     

Ana M. Parra‐Flores  Jesús T. Ponce‐Palafox  lvaro F Barreto‐Altamirano  Milton Spanopoulos‐Hernndez  Sergio G. Castillo‐Vargasmachuca  Gabriela Gaxiola  Hctor Esparza‐Leal  Apolinar Santamaría‐Miranda 《Aquaculture Research》2020,51(9):3652-3663

The objectives of this study were to evaluate the effects of non‐traditional plant and animal protein for river prawn M. americanum on in vivo versus in vitro digestibility in addition to growth performance. In this study, ten ingredients were used: coconut meal, jackfruit meal, soybean meal, poultry by‐product meal, squid meal and fish meal. In vivo studies were conducted using the zeolite marker method, whereas in vitro digestibility was determined by the pH‐stat method using river prawn hepatopancreas enzymes. According to the findings, river prawns digest animals more efficiently than plant ingredients, with squid and fish meal showing a tendency of higher values. Fish meal (53.66%), squid meal (48.52%) and jackfruit meal (42.21%) were found to have a digestibility greater than 40% in in vivo and in vitro methods, thus suggesting that they are the best ingredients used in this study. This also validates their inclusion in practical diets. The correlation of digestibility of in vivo and in vitro was low (R² = .6749). The highest daily weight gain was recorded in the diets containing jackfruit, coconut and squid. Given that the potential of no‐conventional plant ingredients available regionally was significantly higher, this underscores the need to conduct further research to validate their inclusion in practical diets.  相似文献   

Effects of Wheat Starch and Gluten on Tortilla Texture     

Linfeng Wang  Rolando A. Flores 《Cereal Chemistry》1999,76(5):807-810

Wheat starches were isolated from three wheat flours. Two vital wheat glutens, one from a commercial source and another one isolated from straight-grade flour, were combined with wheat starches to form reconstituted flours with a protein level of 10%. Several characteristics of tortillas made with the hot-press method were measured. No significant difference (P < 0.05) occurred in texture of tortillas made with hard wheat gluten and soft wheat gluten. Wheat starches did not have any significant (P < 0.05) effect on tortilla stretchability or foldability. Analysis of variance confirmed that wheat starch and gluten had limited effects on tortilla texture. The possible reasons were that the solubles of wheat flour were not included, and the shortening in the tortilla formula interfered with the interaction of gluten and starch.  相似文献   

Composition of Functional Lipids in Hulled and Hulless Barley in Fractions Obtained by Scarification and in Barley Oil     

Robert A. Moreau  Rolando A. Flores  Kevin B. Hicks 《Cereal Chemistry》2007,84(1):1-5

Two cultivars of hulled barley (Thoroughbred and Nomini) and two cultivars of hulless barley (Doyce and Merlin) were scarified to abrade the outer layers of hull and pericarp. The resulting scarification fines fractions were evaluated as potential sources of functional lipids (phyto‐sterols, tocopherols, and tocotrienols). The levels of total phytosterols and total tocotrienols in the barley scarification fine fractions were probably not high enough to justify their use as functional foods. However, the levels of total phytosterols and total tocotrienols in the oils extracted from both whole kernels and scarified fines were both sufficiently high to make it reasonable to consider their potential use as new functional oils. Indeed, the levels of total tocotrienols in barley oils (2,911–6,126 mg/kg of oil) are several‐fold higher than those reported in two other oils that are being marketed as high in tocotrienols: palm oil (530 mg/kg) and rice bran oil (770 mg/kg). The levels of total phytosterols in barley oils range from 1.20 to 9.60 g/100 g of oil.  相似文献