Dough Ball Research Articles

Influence of of extrusion variables on some functional properties of extruded millet-soybean for the manufacture of ‘fura’: A Nigerian traditional food

‘Fura’ is a traditional thick dough ball snack produced principally from millet or sorghum which is common in Northern Nigeria. It is consumed with ‘nono’ (local yoghurt produced from cow milk) or mashed in water before consumption in the form of porridge. The effects of extrusion conditions feed composition (ratio of soybean to millet), percentage moisture wet basis and screw speed (rpm) on the water absorption index (WAI); water solubility index (WSI) and viscosity from millet/soybean flour mixtures were studied using Response surface methodology (RSM) for ‘fura’ processing. Models were developed and appropriate statistical analysis adopted to test the adequacy of the models. The models showed R2 = 0.73, 0.76, 0.74 for WAI, WSI and viscosity, respectively, indicating that the model could be used to navigate the design space. Because some of the stationary points were outside the range of the experiment, graphical optimization was adopted to determine the optimum and predicted values. The optimum levels and the corresponding predicted values were obtained. The optimal combination of feed composition (17.7% soybean), feed moisture (27.3% wet basis) and screw speed (161 rpm) resulted in optimal WAI of 4.6 g water per g sample. The optimal combination of feed composition (14.77% soybean), feed moisture (15.23%) and screw speed 220 rpm) resulted in optimal WSI of 6.15%. The optimal combinations of feed composition (46.97%), feed moisture (29.34%) and screw speed (174.52 rpm) resulted in optimal viscosity of 4.58 Nsm-2. Key words: Millet, soybean, extrusion, optimization, ‘fura’, water absorption index, water solubility index, viscosity.

Oral inoculation with Salmonella enterica serovar Typhimurium or Choleraesuis promotes divergent responses in the somatotropic growth axis of swine1

Enteric disease and immune challenge are processes that have detrimental effects on the growth performance of young swine. The current study tested the hypothesis that salmonella-induced enteric disease would perturb the endocrine growth axis in a serovar-dependent fashion. Specifically, we evaluated the effects of Salmonella enterica serovar Typhimurium (Typhimurium) and serovar Choleraesuis (Choleraesuis) on critical regulatory components of growth in young swine. Weaned pigs were housed 2 per pen with ad libitum access to feed and water in a 14-d experiment. Pigs were then repeatedly fed 10(8) cfu of either Choleraesuis or Typhimurium in dough balls, with control pigs receiving dough without bacteria. Bacteria were refed twice weekly. Rectal temperatures were monitored daily from d 0 to 7 and ADFI was measured through d 14. Pigs were weighed and samples of serum were obtained for circulating IGF-I on d 0, 7, and 14. At the conclusion of the study, samples of semitendinosus muscle and liver were obtained and subsequently assayed for IGF-I, IGFBP-3, and IGFBP-5 mRNA. Rectal temperatures were elevated in pigs given Choleraesuis from d 2 through 7 (P < 0.05) when compared with control pigs and pigs fed Typhimurium. Pigs receiving Choleraesuis had a substantially decreased feed intake on d 2, 3, 4, 7, 8, 9, and 10 (P < 0.01), with a trend for a reduction on d 5 (P = 0.08), and they experienced an approximately 25% reduction in BW compared with control pigs and pigs given Typhimurium by the conclusion of the study. Pigs given Choleraesuis also experienced marked reductions in circulating IGF-I on d 7 (P < 0.01 vs. control and Typhimurium), with reductions of lesser magnitude on d 14 (P = 0.07 vs. control and P < 0.05 vs. Typhimurium). Inoculation tended to affect liver IGFBP-3 mRNA (P = 0.08), for which expression tended to be elevated in pigs given Typhimurium and Choleraesuis. In contrast, IGFBP-3 mRNA relative abundance was increased (P < 0.03) in pigs given Typhimurium compared with control pigs. Muscle IGF-I mRNA was reduced in pigs given Choleraesuis compared with control pigs and pigs given Typhimurium (P < 0.05). Treatment tended to affect muscle IGFBP-3 mRNA (P = 0.10). Oral inoculation of growing pigs with Choleraesuis disrupted feed intake and BW gain, and this was accompanied by decreases in circulating IGF-I and reduced muscle expression of mRNA for IGF-I and IGFBP-3.

STUDIES ON EFFECT OF SHEETING METHODS ON THE EXPANSION OFPAPADSDURING DEEP FAT FRYING USING SCANNING ELECTRON MICROSCOPY

ABSTRACT Scanning electron microscopy (SEM) studies were used to evaluate the distribution/alterations of the cellular matrix of the deep-fat-fried papads, which are traditional food adjuncts of India. Papad is a thin circular sheet made from dough containing blackgram (Phaseolus mungo), common salt and spices in various proportions. The circular sheets are made from the dough by pressing the spherical-shaped dough balls. The method of pressing the dough affects the cellular structure and hence the diametrical expansion of papads during deep fat frying, which is a desirable quality attribute for the papads. In the present study, papads were prepared by employing three different methods of sheeting the dough, viz., by using a wooden roller pin, by using the thumb and by using a mechanical press. Papads produced by these three different methods were deep fat fried, and % expansions were calculated after deep fat frying. Fried papads were subjected to SEM to understand the distribution/alteration of the matrix by different sheeting methods. The SEM micrographs of the thumb-pressed papads showed that they had good distribution of the protein–carbohydrate matrix, thereby achieving the highest diametrical expansion, followed by wooden pin-rolled papads, then by machine-pressed papads. PRACTICAL APPLICATIONS Papads are made commercially at different levels of production, viz., cottage scale, small scale or medium scale. There are different methods of making papad sheets; using a wooden roller pin, thumb pressing or by mechanical pressing are some important methods. The method of making the papad sheet affects the diametrical expansion of papads during deep fat frying, which is a desirable quality attribute commercially. The present study indicates that the thumb pressing method is effective for better expansion. The results have been corroborated with scientific studies using SEM data, which indicated better distribution of protein-carbohydrate matrix. The thumb pressing method of making papad sheets is also helpful for generation of employment in developing countries.

Effect of microwave heating of wheat grains on the browning of dough and quality of chapattis

SummaryStudies were conducted to evaluate the effect of microwave (900 W, 2450 MHz) heating of wheat grains conditioned to different moisture levels on the activity of polyphenol oxidase (PPO) and subsequent colour changes during storage of wheat dough. The results showed that microwave heating of wheat grains for 80 s decreased the PPO activity significantly (P ≤ 0.05) with an increase in moisture level from 12 to 18%. Whole wheat flour milled from microwave treated wheat grains (80 s, 18% MC) had 93.39% less activity of PPO. The dough balls (40 g), pressed and rolled into circular form (150.00 mm diameter and 2.00 mm thickness) and stored at 5–6 °C for 72 h. The colour of flattened circular dough was measured using Hunter Colour Meter and it was found that L‐value (lightness) decreased from 64.21 to 60.23 in treated and from 64.79 to 47.93 in control samples after 72 h of storage. The results showed that the microwave heating effectively controlled the enzymatic browning in dough and improved the consumer acceptability of chapattis prepared from the same during refrigerated (5–6 °C) storage for 72 h.

Effects of feeding Salmonella enterica serovar Typhimurium or serovar Choleraesuis on growth performance and circulating insulin-like growth factor-I, tumor necrosis factor-α, and interleukin-1β in weaned pigs1

The most common Salmonella serovars causing clinical disease in pigs are Salmonella enterica serovars Typhimurium (Typhimurium) and Choleraesuis. Given that the swine host-adapted serovar Choleraesuis has been reported to cause systemic disease, a different disease outcome from that of Typhimurium, our working hypothesis was that this serovar would likely engage systemic immune-inflammatory mechanisms, resulting in elevated systemic cytokine secretion. Forty-eight weaned pigs were blocked by BW and sex, and randomly allotted to 1 of 3 treatments in a 14-d study. Each treatment had 8 replicates (pens), with 2 pigs/pen. The treatments consisted of a negative control and pigs repeatedly fed 10(8) cfu of Typhimurium or Choleraesuis. On d 0, the pigs were fed Choleraesuis or Typhimurium in dough balls, and the bacteria were refed twice weekly throughout the experiment. Control pigs received dough balls without bacteria. All pigs were housed in temperature-controlled rooms under constant lighting and were fed a standard corn-soybean meal-based nursery diet. Pig BW and feed disappearance were used to determine ADG, ADFI, and G:F. Rectal temperatures were obtained daily from 1 pig/pen beginning 2 d before the first bacterial feeding through d 7 using rapid-response digital thermometers. Serum was collected on d 0, 7, and 14 from a single pig/pen for analysis of IGF-I, tumor necrosis factor-alpha , and IL-1beta. There was no change in the rectal temperature of the control or the Typhimurium-challenged pigs (compared with d 0) or when comparing Typhimurium-challenged pigs with control animals. In contrast, pigs fed Choleraesuis had increased rectal temperatures beginning on d 2 and continuing through d 7 (P < 0.05), with the greatest elevation on d 3 (P < 0.001) compared with the control pigs. Average daily gain and ADFI of pigs challenged with Typhimurium did not differ from those of the control animals. Pigs fed Choleraesuis had a 25% reduction in ADG (P < 0.0001) and ADFI (P < 0.002) compared with the control pigs. On d 7, pigs fed Choleraesuis had reduced serum IGF-I compared with control (P < 0.01) or Typhimurium-challenged pigs (P = 0.01). Bacterial feeding did not affect serum tumor necrosis factor-alpha or IL-1beta compared with control pigs at any time throughout the experiment. We conclude that repeated exposure of weaned pigs to Choleraesuis reduced growth performance in the absence of changes in systemic inflammatory cytokines.

Modeling the mechanisms of dough puffing during vacuum microwave drying using the finite element method

A two-dimensional finite element (2-D FE) model was developed in order to simulate the puffing of a dough ball being dehydrated under vacuum with microwave energy. The model enabled the coupling of thermal and solid mechanics effects providing an insight into the mechanisms of puffing of food stuffs during vacuum microwave dehydration. The model predicted the rise in temperature reasonably well for low salt contents. The model suggests puffing is due to two mechanisms: first, the difference in pressure between air trapped in the dough and the chamber pressure of the vacuum microwave dehydrator; second, the generation of vapour due to the temperature rise in the dough. The temperature distribution is primarily determined by the penetration depth of the microwaves into the material. It was further shown that the partial collapse of dough balls in the later stages of the drying process can be attributed to the softening of dough at higher temperatures and air loss throughout the drying process.

Using a Force Plate to Correct Student Misconceptions

Each year during the unit on collisions I ask my physics students this conceptual question: If you want to close a door but you have too much inertia at the moment to get up and do it yourself, should you throw a ball that rebounds well, like a basketball, or a ball that rebounds poorly, like a ball of modeling dough, at the door?1 I also impose the condition that the two balls must have the same momenta when they strike the door. I give my students some time to discuss the problem in small groups and then make a prediction. I find that most students predict incorrectly that the dough ball will be more effective at closing the door because it is solid throughout and denser than the hollow, air-filled basketball. The students do not focus on the better-rebounding basketball and the greater change in velocity that it experiences than the modeling dough ball when they strike a solid object like a door. To correct this misconception I use a Vernier2 force plate to measure the impulse of a size 3 basketball and a ball of modeling dough of equal mass (0.3213 ± 0.0002 kg) dropped from the same height of 0.200 ± 0.002 m, to ensure equal velocities, onto the force plate. While I realize that a collision between a ball and a force plate is not exactly the same as a collision between a ball and a door, a more complex system, I believe it offers some very useful insights into the problem. I also include in this paper an extension on validating the impulse-momentum theorem.

Determination of convective heat transfer coefficient during frying of potato dough

In this study, the influence of oil temperature, water migration and surface temperature of potato dough ball on convective heat transfer coefficient was investigated. The convective heat transfer coefficient during deep-fat frying was determined at temperatures 160, 170, 180 and 190 °C. The dough ball of wheat flour with different amounts of whole potato flour having a radius of 2.5 cm was used as a sample. Heat transfer coefficient was the highest at the beginning of deep-fat frying process (197.25 ± 1.39 to 774.88 ± 3.90 W/m 2 K), and the lowest in the case of setting up a uniform period of water migration from sample, which corresponded to surface temperatures slightly higher than 100 °C (94.22 ± 0.33 to 194.84 ± 0.91 W/m 2 K). Addition of whole potato flour in dough considerably decreased heat transfer coefficient regardless of the frying oil temperature. Higher oil temperature for deep-fat frying increased values of heat transfer coefficient for the same composition of spherical shape dough.

Potential of Triticale as a Substitute for Wheat in Flour Tortilla Production

ABSTRACTThe potential of triticale as a partial or total substitute for wheat in flour tortilla production was evaluated. Different mixtures of triticale and wheat flours were tested in a typical hot‐press formulation. Both grains yielded similar amounts of flour. Wheat flour contained 1.5% more crude protein, 1.6× more gluten, and produced stronger dough than triticale. Triticale flour significantly reduced optimum water absorption and mix time of blends. Flour tortillas with 100% triticale absorbed 8% less water and required 25% of the mix time of the control wheat flour tortilla. The yield of triticale tortillas was lower than the rest of the tortillas due to lower moisture content and water absorption. Triticale dough balls required less proofing and ruptured during hot pressing, thus producing defective tortillas. The 50:50 flour mixture produced doughs with acceptable rheological properties and good quality tortillas. Addition of 1% vital gluten to the 75:25 triticale‐wheat flour mix or 2% to the 100% triticale flour significantly increased water absorption and mix time and improved dough properties and tortilla yields. Textural studies indicated that increasing levels of triticale flour reduced the force required to rupture tortillas. For all tortilla systems, rupture force gradually increased, and extensibility decreased during seven days of storage at room temperature; the highest rate of change occurred during the first day. Sensory evaluation tests indicated that triticale could substitute for 50% of wheat flour without affecting texture, color, flavor, and overall acceptability of tortillas. For production of 100% triticale flour tortillas, at least 2% vital gluten had to be added to the formulation.

The effects of tannin and protein on food preference in eastern grey squirrels

Although some mammalian generalist herbivores avoid foods high in plant secondary compounds, it has not been adequately shown that eastern grey squirrels (Sciurus carolinensis), who regularly encounter tannin in acorns, avoid high tannin diets. Dietary tannin can inhibit nitrogen assimilation; hence herbivores that eat tannin should seek high protein diets to compensate. I presented freeranging grey squirrels with four types of dough balls that differed in tannin and protein content. Squirrels consistently preferred low to high tannin foods but did not distinguish between low and high protein foods. Intensity of preference for low tannin foods was greatest during early to mid autumn, when food is relatively abundant, and declined into the spring and early summer, when food is relatively scarce. Food availability, partitioning foraging effort between eating and scatterhoarding, physiological competence, and nutrient complementarity may explain why squirrels consume tannin in natural diets, in spite of preference for low tannin dough balls demonstrated here.