Research Note: Producing lean poultry meat composite gels with different carbohydrate-based breadcrumbs.

The effects of using different breadcrumbs (3 wheat, 2 gluten-free: pea and rice) to improve yield and modify the texture of a lean poultry product were evaluated. All breadcrumbs significantly reduced cooking loss (P < 0.05), with one of the wheat crumbs showing the best results (35% reduction). Light microscopy revealed that breadcrumbs were well connected to the cooked meat matrix, and fully hydrated, that is, forming well-structured composite gels. The presence of breadcrumbs resulted in lower hardness, chewiness, and gumminess values of 3 of the treatments (compared to the control with no breadcrumbs), while the other 2 did not affect those parameters. Overall, selected breadcrumbs that are commonly used in ground beef products can be employed to improve yield/modify texture in poultry products but have to be selected to address certain needs.

Effects of plant and dairy proteins on the texture and microstructure of lean turkey meat batters.

The effect of using non-meat proteins (pea, faba, rice, whey, and caseinate; 2% level) on the texture, yield, and structure of lean turkey meat batters was compared to an all-meat control and a control with 2% added meat proteins. The best overall proteins were caseinate (animal derived) and pea (plant derived) which reduced cooking loss (P < 0.05, 60% compared to the two controls), while also increasing hardness over the first control treatment. Rice protein also increased hardness (P < 0.05) but did not reduce cooking loss compared to the first control. Part of this could also be seen under the microscope, where the caseinate and faba treatments showed denser microstructure compared to the rice and whey protein treatments; both had higher cooking loss. Overall, the meat industry is continuously searching for non-meat ingredients to enhance texture and yield and this study provides ranking of some new protein preparations.

Structural and functional properties of modified cellulose ingredients and their application in reduced-fat meat batters.

The first goal for this experiment was to determine the structural and technological characteristics for methylcellulose (MC), carboxymethyl cellulose (CMC), and microcrystalline cellulose (MCC), while the subsequent goal for this experiment was to determine the application of the modified cellulose ingredients in reduced-fat meat batters. Each ingredient was characterized and then evaluated as a fat replacer using meat batters with targeted fat levels of 20%, 10%, and 5%. It was determined that each modified cellulose ingredient was unique in its structural and technological properties which caused significant effects on the physiochemical properties of the meat batters. Specifically, MC created inconsistences during heating and cooling of meat batters resulting in elevated cooking loss but did not change textural hardness of cooked samples, CMC appeared to interfere with the meat batter matrix resulting in lower textural hardness but maintained levels of cooking loss, and MCC had similar levels of cooking loss and textural hardness when compared with the control samples.

Influence of Different Stainless Steel Finishes on Biofilm Formation by Listeria monocytogenes.

ABSTRACT: Biofilm formation of Listeria monocytogenes on stainless steel, a widely used abiotic surface in the food processing industry, was investigated by focusing on the attachment tendency and behavior of L. monocytogenes 08-5578 on eight different stainless steel surfaces: glass bead blasted (rough and fine), deburred (Timesaver), drum deburred, pickled, pickled and drum polished, electrolytic polished, and cold rolled (untreated control). The aim was to see whether there are finishes with significantly lower bacterial attachment. Surface roughness data (measured via four roughness parameters), determined by interferometry, was also compared with the number of adhering cells to detect possible correlations. Cultivation of L. monocytogenes biofilms was carried out using a CDC biofilm reactor with 1% tryptic soy broth set at 20°C for 4, 8, and 24 h. In addition, a cultivation trial was run with continuous nutrient flow (1% tryptic soy broth, 6.2 mL/min) for 24 h. Eight-hour results showed a significant difference (P < 0.05) in biofilm cell counts in biofilms between the glass bead-blasted surfaces (3.23 and 3.26 log CFU/cm2 for the fine and rough, respectively) and deburred (Timesaver) surface (2.57 log CFU/cm2), between drum deburred and deburred (Timesaver) surface (3.41 versus 2.57 log CFU/cm2), and between drum deburred and pickled surface (3.41 versus 2.77 log CFU/cm2). Data gained after 4-h, 24-h, and 24-h plus an additional 24-h continuous flow cultivation showed no significant difference in attachment among surfaces. No correlation between roughness data and attachment was found after all four incubation times, suggesting that roughness values, at these ranges, are insufficient in determining the surfaces' affinity to bacteria. Overall, this study suggests that roughness values cannot be used to predict the degree of L. monocytogenes attachment to a specific stainless steel surface.

Impact of fiber on growth, plasma, gastrointestinal and excreta attributes in broiler chickens and turkey poults fed corn- or wheat-based diets with or without multienzyme supplement.

Effects of fiber on growth performance, gizzard attributes, ileal digesta viscosity, plasma uric acid (PUA) and excreta characteristics were investigated in broiler chickens (experiment 1) and turkey poults (experiment 2) fed corn or wheat-based diets with or without multienzyme supplement (MES). Fibrous diets were created by adding 10% corn distillers dried grains with solubles or wheat middlings in corn or wheat-based diets, respectively. The MES had main activities of xylanase and ß-glucanase. A total of 960-d old Ross x Ross 708 male chicks and 720-d old male Hybrid toms were allocated to eight grain, fiber and MES combinations to give 6 replicates per combination. In each experiment, birds had free access to feed and water for 28 days. Excreta samples were collected for 3-d prior to the end and on d 28, body weight and feed intake were recorded, birds bled and subsequently necropsied for gastrointestinal samples. There was an interaction (P ≤ 0.036) between grain, fiber and MES in broilers final body weight (FBW) and BW gain (BWG). In this context, high fiber corn diets reduced FBW and BWG and supplementation of MES improved these parameters. Broilers fed corn had a higher (P < 0.05) FBW (1,462 vs. 1,424 g) and BWG (1,416 vs. 1,378 g) than birds fed wheat diets. Broilers fed corn-based diets without fiber diets had a higher ileal viscosity and excreta moisture compared to birds fed wheat-based and high fiber diets. Broilers fed low fiber wheat diets without MES had higher (P < 0.05) PUA concentration compared to birds fed low fiber corn diets without MES. Poults fed wheat diets had a higher (P < 0.05) FBW (1,441 vs. 1,408 g) and BWG (1,376 vs. 1,343 g) than poults fed corn diet. The MES supplementation in corn-based diets rich in fiber increased (P = 0.03) gizzard weight in poults. In conclusion, there were varied growth and physiological responses in broilers and turkey suggesting the need for refining enzyme application for different poultry species.

Organogels use in meat processing - Effects of fat/oil type and heating rate.

The effects of fat/oil type (regular and rendered beef fat, canola, soy and flaxseed oils), form (native or organogel), and heating rate (0.7 and 3.5 °C/min) were investigated in a comminuted meat system. Converting beef fat to organogel resulted in higher hardness values of the cooked meat products, but the opposite was observed with the vegetable oils. Springiness was lower for all organogels compared to the native fat/oil used. Fat globule size was larger in the organogels prepared from vegetable oils compared to the native oils, but that was not the case for beef fat. Increasing heating rate reduced cooking loss, and while employing organogels did not affect the regular beef fat, it significantly increases losses from the vegetable oil treatments. Overall, using the organogel technology should be attractive to processors and consumers alike as products with high unsaturated fatty acids can be produced.

Water immobilization by glass microspheres affects biological activity.

We recently reported that the water holding capacity of myofibrillar protein hydrogels could be increased upon addition of small amounts of microparticles, particularly glass microspheres. Glass microspheres were found to decrease the spin-spin relaxation time (T2) of water protons in the gels, which was interpreted as enhanced water binding by the glass. We were thus interested in determining whether the observed effects on water proton relaxation were a direct consequence of water-glass interactions. Here we show how glass microspheres reduce the mobility of pure water, reflected in large decreases in the T2 of water protons, decreases in the self-diffusion coefficient of water molecules, a lower water activity, and strengthening of O-H bonds. Even though glass is considered an inert material, glass microspheres were shown to inhibit the growth of human embryonic kidney cells, and stimulate or inhibit the growth of leukemia and monocytic lymphoma cells in vitro, depending on dose and time. The germination of alfalfa seeds and the growth of E.coli cells were also inhibited upon exposure to glass microspheres. This work indicates that the properties and behavior of materials, even ones considered inert, can be affected by their size. These observations suggest possible toxicological consequences of exposure to microparticles, but also open us possibilities to affect cellular/organism function via modulation of macromolecular hydration.

Quality effects of using organogels in breakfast sausage.

Organogels made with canola oil, ethyl cellulose (EC; 8, 10, 12 and 14%), and sorbitan monostearate (SMS; 1.5, 3.0%) were used to replace pork fat in breakfast sausages. Some of the formulations with SMS matched the objective hardness (texture analyzer) of the pork fat control; however, sensory hardness was not so easily matched. Using canola oil by itself resulted in lower objective and subjective hardness values than the control. Sensory cohesiveness was not affected by the replacements, but springiness was lower in the treatments without SMS and some of the high EC treatments with SMS. Lightness of organogel treatments was lower than the control, but redness and yellowness values were not affected. Sensory juiciness and oiliness were in general lower in the organogel treatments. Overall, the study demonstrates the potential for the use of organogels in coarse ground meat products, as a means of improving the nutritional profile by replacing saturated fat with mono and poly unsaturated oils.

Potential use of organogels to replace animal fat in comminuted meat products.

The replacement of beef fat (BF) with regular or structured canola oil [organogel produced with ethylcellulose (EC) 0.0%, 1.5% or 3.0% sorbitan monostearate (SMS)] was conducted in frankfurters. Substitution with regular oil doubled the hardness of the frankfurters relative to BF. Using an organogel prepared with 8% EC and 1.5 or 3.0% SMS resulted in a hardness value similar to that of BF, by both sensory and texture profile analysis. Without SMS addition, sensory results showed (P<0.05) lower hardness values than regular oil but still higher than BF. Gels prepared using higher EC concentrations (12 and 14%) yielded meat products with a higher sensory hardness than BF (P<0.05). Liquid oil based frankfurters had very small fat globules compared to BF, but structuring the oil yielded larger fat globules. Color measurements indicated that oil-containing frankfurters were lighter than the ones with BF. Smokehouse yields were generally higher for canola oil and organogel containing treatments compared to the beef fat treatment. When SMS was included, fat losses increased over the canola oil treatment. The results demonstrate the possibility to use organogels to replace beef fat and depending on the formulation to manipulate textural properties to resemble traditional products but with lower saturated fat content.

Effect of Gradual Heating and Fat/Oil Type on Fat Stability, Texture, Color, and Microstructure of Meat Batters.

The effects of endpoint cooking temperature (40, 50, 60, 70, 80, and 90 °C) on emulsion stability, texture, color, and microstructure of meat batters prepared with different fats/oils were studied. Canola oil treatments showed the highest cooking loss whereas hydrogenated palm oil provided the most stable meat batters. Rendered beef fat was less stable than regular beef fat. Increasing endpoint cooking temperatures resulted in a progressive reduction of water holding capacity in all treatments. As temperature was raised, meat batters showed higher hardness and cohesiveness values, but no appreciable changes in cohesiveness above 60 °C. Canola and hydrogenated palm oil treatments showed the highest hardness and chewiness values. Lightness (L(*) ) values of all meat batters increased significantly with increasing temperature from 40 to 60 or 70 °C; no major changes observed above 70 °C. Light microscopy revealed no substantial changes in the microstructure of all the stable meat batters cooked to between 50 and 70 °C. Heating to 90 °C changed the microstructure in all meat batters except the hydrogenated palm oil treatments, which still showed nonround fat particles and a less aggregated protein matrix.

Effects of Organogel Hardness and Formulation on Acceptance of Frankfurters.

Different organogel formulations used as beef fat (BF) replacement (0%, 20%, 40%, 60%, and 80%) were utilized to optimize the mechanical properties of frankfurters. Organogels, made of canola oil (CO), included different concentrations of ethyl cellulose (EC) and sorbitan monostearate (SMS). They consisted of: 8% EC + 1.5% SMS referred to as organogel-I (OG-I), 8% EC + 3.0% SMS (OG-II), and 10% EC + 1.5% SMS (OG-III), which were found promising in a previous study when used at 100% replacement. Replacement of BF with organogels at all levels could bring down the very high hardness values (texture profile analysis and sensory) of frankfurters prepared using CO by itself, relative to the BF control. OG-I and OG-II quantity had no significant effect on hardness and springiness, being similar in many cases to the BF and lower than the CO control. Shear force values of all organogel treatments were not significantly different from one another, and were between the BF and CO controls. Smokehouse yield showed a pattern of decreasing losses with increasing organogel replacement level. Sensory analysis revealed that using CO by itself significantly increased hardness, but structuring the oil (via organogelation), brought it down to the BF control value in all OG-I and OG-II formulations. Juiciness was significantly reduced by using liquid oil but increased with raising the amount of organogels. Oiliness sensation increased with higher organogel substitution and was actually higher than the beef control. The study demonstrates the potential use of vegetable oil structuring in replacing the more saturated BF in emulsion-type meat products.

Influence of solvent quality on the mechanical strength of ethylcellulose oleogels.

Ethylcellulose (EC) is the only known food-grade polymer able to structure edible oils. The gelation process and gel properties are similar to those of polymer hydrogels, the main difference being the nature of the solvent. The present study examines the influence of solvent quality on the large deformation mechanical behavior of EC oleogels. Two alternative strategies for manipulating the mechanical response of these gels were evaluated; manipulating the bulk solvent polarity and the addition of surface active small molecules. Gel strength was positively correlated to solvent polarity when blending soybean oil with either mineral oil or castor oil. This behavior was attributed to the ability of the polar entities present in the oil phase to interact with the EC gel network. The addition of the small molecules oleic acid and oleyl alcohol resulted in a substantial enhancement in gel strength up to 10wt% addition, followed by a gradual decrease with increasing proportions. Binding interactions between EC and these molecules were successfully modeled using a Langmuir adsorption isotherm below 10wt% addition. Furthermore, the thermal behavior of stearic acid and stearyl alcohol also indicated a direct interaction between these molecules and the EC network. Differences in the mechanical behavior of gels prepared using refined, bleached, and deodorized canola or soybean oils, and those made with cold-pressed flaxseed oil could be attributed to both oil polarity, and the presence of minor components (free fatty acids). Shorter pulsed NMR T2 relaxation times were observed for stronger gels due to the more restricted mobility of the solvent when interacting with the polymer. This work has demonstrated the strong influence of the solvent composition on the mechanical properties of EC oleogels, which will allow for the tailoring of mechanical properties for various applications.

The role of surfactants on ethylcellulose oleogel structure and mechanical properties.

The effects of surfactant addition to ethyl-cellulose (EC) based oleogels were examined with respect to the chemical nature of the "head" and "tail" groups of the surfactant. Unique sigmoidal temperature dependent rheological behavior was observed upon surfactant addition, suggesting additional organized structure formation. Glycerol-based surfactant addition lead to greatest decrease in the sol-gel and gel-sol transition temperatures compared to sorbitan-based surfactants. This behavior can be attributed to the plasticizing nature of the small head group of glycerol compared to the larger head group of sorbitan surfactants. A significant increase in the penetration force of the gels was observed upon surfactant addition, suggesting possible surfactant-polymer interactions which stiffen the polymer network. Thermal analysis detected a reduction in both SMS and GMS crystallization peak temperature and enthalpy. In the case of GMS, two melting peaks were observed upon EC addition to the oil phase, suggesting EC/surfactant interactions. These results demonstrate the effects of surfactant head group structure on EC oleogel rheological properties.

The gelation of oil using ethyl cellulose.

The characterization of the thermo-gelation mechanism and properties of ethyl cellulose/canola oil oleogels was performed using rheology and thermal analysis. Thermal analysis detected no evidence for thermal transitions contributed to secondary conformational changes, suggesting a gelation mechanism that does not involve secondary ordered structure formation. Rheological analysis demonstrated a relationship between the polymer molecular weight and the final gel strength, the cross-over behavior as well as the gel point temperature. Increasing polymer molecular weight led to an increase in final gel strength, the modulus at cross-over, and the gel point temperature. Cooling/heating rates affect gel modulus only for the low molecular weight samples. A decrease in gel strength with increasing cooling rate was detected. The cross-over temperature was not affected by the cooling/heating rates. Cooling rate also affected the gelation setting time where slow cooling rates produced a stable gel faster.

Microstructure, texture and colour development during crust formation on whole muscle chicken fillets.

1. The development of crust during a 22-min period was evaluated in an oven, and in previously cooked-in-bag products (no crust) placed in an oven for 10 min. The oven-roasted products started to develop a thin (2-4 µm) crust layer after 4 min. At that point, the colour of the fillets turned white but no browning was observed. As roasting time increased, crust thickness and shear force increased, the product turned brown and eventually black at certain spots. 2. Light microscopy revealed the shrinking of muscle fibres close to the surface, as they also lost water. At a certain point, tears between the different layers started to appear. The inner muscle fibres also progressively shrank and the spaces between them increased. Microscopy of cook-in-bag products revealed no crust formation during heating. Upon moving to the oven, crust started to form but was much faster compared with the other products. 3. Cook-in-the-bag samples showed a higher rate of cook loss during the first 12 min (to internal 70°C) compared with oven heating. This could have been due to the fast heating rate in water and/or no crust formation. 4. White colour was fully formed on water-cooked fillets within 2 min (L* = 83), while it was gradually forming on oven-roasted samples (max L* of 79 after 12 min). 5. Shear force measurements showed an increase in both treatments up to 18 min, with a decrease thereafter (when dry crust started to crack).

Effect of inulin, ß-Glucan and their mixtures on emulsion stability, color and textural parameters of cooked meat batters.

The effects of fat level (20.0, 12.5 and 5.0%), Inulin (gel-IG, and powder-IP) and ß-Glucan (ßG) on emulsion stability, color, textural characteristics and microstructure of cooked meat batters were investigated. Reducing fat to 5.0% increased cooking loss and decreased emulsion stability, lightness, hardness and fracturability of cooked emulsions. Inulin, ßG, and their mixtures were used as fat replacers in low fat formulations. Adding IP provided better emulsion stability compared to IG, which had no significant effect on stability. IP also produced harder (27-34 N) low fat products with a high fracturability (26-29 N). On the contrary, emulsions containing IG resulted in creamy and softer characteristics. The results were supported by light micrographs, which indicated that appropriate addition of IG and ßG mixtures (3%-IG & 0.3%-ßG, 6%-IG & 0.6%-ßG) could compensate for some of the changes brought about by fat reduction, and maintained several of the textural characteristics of the product as well as reducing cook loss.

Fat reduction in comminuted meat products-effects of beef fat, regular and pre-emulsified canola oil.

The effects of fat reduction (25.0%, 17.5%, and 10.0%) and substituting beef fat with canola oil or pre-emulsified canola oil (using soy protein isolate, sodium caseinate or whey protein isolate) on cooking loss, texture and color of comminuted meat products were investigated. Reducing fat from 25 to 10% increased cooking loss and decreased hardness. Canola oil or pre-emulsified treatments showed a positive effect on improving yield and restoring textural parameters. Using sodium caseinate to pre-emulsify the oil resulted in the highest hardness value. Cohesiveness was affected by fat type and level. The color of reduced fat meat batters was darker for all, except the beef fat treatments. Using canola oil or pre-emulsified oil resulted in a significant reduction in redness. The results show that pre-emulsification can offset some of the changes in reduced fat meat products when more water is used to substitute for the fat and that pre-emulsification can also help to produce a more stable meat matrix.

Effects of two types of soy protein isolates, native and preheated whey protein isolates on emulsified meat batters prepared at different protein levels.

The effects of substituting 1.5% of the meat proteins with low gelling soy protein isolate (LGS), high gelling soy protein isolate (HGS), native whey protein isolate (NWP), and preheated whey protein isolate (PWP) were compared at varying levels of proteins (12, 13 and 14%), with all meat control batters prepared with canola oil. Cooking losses were lower for all the non-meat protein treatments compared to the all meat controls. When raising the protein level from 12 to 14%, cooking losses increased in all treatments except for the NWP treatments. Using LGS increased emulsification and resulted in a more stable meat batters at the 13 and 14% protein treatments. Textural profile analysis results showed that elevating protein level increased hardness and cohesiveness. The highest hardness values were obtained for the PWP treatments and the lowest for the HGS, indicating a strong non-meat protein effect on texture modification. Non-meat protein addition resulted in lighter and less red products (i.e., lower red meat content) compared to the all meat controls; color affected by non-meat protein type. Light microscopy revealed that non-meat proteins decreased the frequency of fat globules' agglomeration and protein aggregation. The whey protein preparations and HGS formed distinct "islands" within the meat batters' matrices, which appeared to interact with the meat protein matrix.

Physicochemical effects of the lipid phase and protein level on meat emulsion stability, texture, and microstructure.

The effects of beef fat (25%) substitution with rendered beef fat, canola oil, palm oil, or hydrogenated palm oil at varying meat protein levels (8%, 11%, and 14%) were studied in emulsified beef meat batters. There was no significant difference in fat loss among meat batters made with beef fat, rendered beef fat, or palm oil. Hydrogenated palm oil provided the most stable batters at all protein levels. Increasing meat protein to 14% resulted in high fat loss in batters prepared with canola oil, which did not occur in the other formulations. This indicates that the physicochemical characteristics of fat/oil affect emulsion stability. Cooked batter hardness was higher (P < 0.05) when protein level was raised; highest in hydrogenated palm oil batters when compared at similar protein levels. As protein level was raised springiness values were increased in all the meat treatments. Springiness was higher in the canola oil treatments. Light microscopy revealed fat globule coalescence in canola oil meat batters prepared with 14% protein, as well as the development of fat channels and more protein aggregation; both seem to result in lower emulsion stability. Hydrogenated palm oil batters showed fat particles with sharp edges as opposed to the round ones seen in all other treatments.