Effects of fat level, oat fibre and carrageenan on frankfurters formulated with 5, 12 and 30% fat

The effects of fat level (5, 12 and 30%), carrageenan and oat fibre on the hydration/binding properties, colour and flavour characteristics of frankfurters were investigated. Decreasing the fat content from 30% to 5% significantly increased cook loss and decreased water holding capacity and emulsion stability. Reduced-fat products were also darker and redder compared with the 30% fat controls. Addition of carrageenan or oat fibre reduced cook loss and increased both water holding capacity and emulsion stability. Sensory evaluation indicated that decreasing fat from 30% to 5% increased the intensity of smokiness, spiciness and saltiness and reduced the overall acceptability of the flavour. Carrageenan or oat fibre did not alter the colour of the frankfurters and neither ingredient had a significant effect on the flavour characteristics assessed. The results demonstrate that carrageenan or oat fibre can partially offset some of the changes which occur in low-fat frankfurters when added water replaces fat and protein level is constant.     

Effects of fat level and maltodextrin on the functional properties of frankfurters formulated with 5, 12 and 30% fat

The effects of fat level (5, 12 and 30%) and maltodextrin on emulsion stability, cook loss, colour, texture and sensory characteristics of frankfurters were investigated. Three fat levels (5, 12 and 30%) were formulated containing added maltodextrin. For each fat level a control was prepared without added maltodextrin giving a total of 6 treatments (3×2 factorial design). Reducing the fat from 30 to 5% increased cook loss and decreased emulsion stability. Panellists detected an increase in juiciness and a decrease in overall texture, overall acceptability when the fat level was reduced from 30 to 5%. Instron texture profile analysis showed a decrease in hardness, chewiness and gumminess and an increase in springiness with decreasing fat level. Maltodextrin addition caused a significant decrease in cook loss of the frankfurters but also decreased the emulsion stability. An interactive effect (P<0.05) occurred between fat level and maltodextrin resulting in no significant difference in hardness, gumminess and chewiness values when maltodextrin was present in the reduced-fat (5 and 12%) frankfurters. Saltiness, overall flavour intensity, overall texture and overall acceptability were unaltered (P>0.05) by maltodextrin. The results indicate that maltodextrin can be used as a suitable fat replacer since it offset some of the changes brought about by fat reduction, decreasing cook loss and maintaining a number of textural and sensory characteristics of the frankfurters.     

The influence of carrageenan on the properties of low-fat frankfurters

Research was undertaken to study the technological properties of six carrageenan fractions and their usefulness as fat substitutes in frankfurter type sausages. In the first stage of the experiment hardness of gels made of 3% solutions of carrageenan preparations with different pH (5.5, 6.0 and 6.5) was evaluated. The highest F_max. values were noted in gels obtained from G-WG carrageenan (kappa I fraction). In the second stage of the study frankfurter type sausages were produced, containing 20% and 10% of fat in meat batter with or without (control) kappa I carrageenan (G-WG). Carrageenan as a fat substitute caused a reduction in cooking and storage weight losses, increased hardness, gumminess and chewiness. All frankfurters produced with carrageenan, irrespective of fat content, were characterized by significantly higher sensory evaluation scores for texture, color and taste in comparison to control sausages.     

改性大豆分离蛋白对法兰克福香肠品质的影响

采用酶水解和酶交联的方法对SPI进行改性,制备能够提高法兰克福香肠的持水性和贮存稳定性的功能性食品用蛋白配料.通过应用全质构分析和色差的方法,考察添加改性蛋白的香肠品质,用TBARS反应物的含量来监测改性蛋白对香肠在储藏过程中的脂肪氧化稳定性的影响.结果表明:SPI水解交联产物可以显著(P＜0.05)抑制法兰克福香肠脂肪氧化的发生,显著(P＜0.05)降低香肠的蒸煮损失,显著(P＜0.05)提高香肠的质构品质.采用碱性蛋白酶水解SPI至水解度4后停止水解、再用谷氨酰胺转氨酶交联2 h获得的改性蛋白,以2%的量添加到法兰克福香肠中,其防止香肠蒸煮损失和抗氧化效果显著.     

Effects of three cellulose gums on the texture profile and sensory properties of low fat frankfurters

Composition, textural, viscoelastic, hydration, colour, and sensory attributes of regular and low fat pork/beef frankfurters with and without cellulose gums (carboxymethyl cellulose (CMC) and two types of microcrystalline cellulose (MCC-I and II)) were investigated. Fat was replaced with water in the low fat products. Moisture loss during cooking was reduced in low fat products from 10 to 6% because of the addition of CMC; however, both MCC increased moisture loss by 12–15%. CMC addition also increased the amount of free water. The high fat product was lighter (higher 'L') than the reduced fat frankfurters; gums did not appreciably change the colour. The viscoelastic properties (relaxation time, elastic moduli) were unaffected by the changes in fat level. Product hardness, brittleness, gumminess and chewiness increased with the decrease in fat level. MCC-II improved the textural properties of the low fat product to those of the high fat product. Sensory panel results indicated a decrease in tenderness with low fat and this was not improved by MCC-II. Overall, acceptability scores indicated that all the products (high and low fat) were acceptable.     

Composition of dietary fibre in cocoa husk

 This paper describes the total non-starch polysaccharide (NSP), soluble and insoluble dietary fibre (SDF and IDF) content of processed cocoa husk (cocoa butter <3 g/100 g) determined according to Englyst's enzymatic-chemical procedure. In addition, fibre values were determined by measuring the levels of the composite sugars by spectrophotometry and gas chromatography methods, and the fractions acid-detergent fibre, neutral-detergent fibre, crude fibre, Klason lignin, starch, crude protein, ash, fat, water content, and water-holding capacity (WHC). The NSP content was 43.8±2.32 g/100 g (28.34 g/100 g IDF plus 15.60 g/100 g SDF), the mean soluble fibre concentration was 35.5% of total fibre. Klason lignin content, estimated gravimetrically, was 13.7±1.8 g/100 g. Cellulose (19.7±1.48 g/100 g) and uronic acids (12.4±1.35 g/100 g) were the main type of IDF and SDF substances, respectively. The analysis of neutral sugar constituents showed the presence of glucose, the predominant sugar, followed by arabinose, galactose and xylose. The WHC was 3.62±0.47 g water/g cocoa husk. Received: 19 December 1997 / Revised version: 27 February 1998     

Composition of dietary fibre in cocoa husk

 This paper describes the total non-starch polysaccharide (NSP), soluble and insoluble dietary fibre (SDF and IDF) content of processed cocoa husk (cocoa butter <3 g/100 g) determined according to Englyst's enzymatic-chemical procedure. In addition, fibre values were determined by measuring the levels of the composite sugars by spectrophotometry and gas chromatography methods, and the fractions acid-detergent fibre, neutral-detergent fibre, crude fibre, Klason lignin, starch, crude protein, ash, fat, water content, and water-holding capacity (WHC). The NSP content was 43.8±2.32 g/100 g (28.34 g/100 g IDF plus 15.60 g/100 g SDF), the mean soluble fibre concentration was 35.5% of total fibre. Klason lignin content, estimated gravimetrically, was 13.7±1.8 g/100 g. Cellulose (19.7±1.48 g/100 g) and uronic acids (12.4±1.35 g/100 g) were the main type of IDF and SDF substances, respectively. The analysis of neutral sugar constituents showed the presence of glucose, the predominant sugar, followed by arabinose, galactose and xylose. The WHC was 3.62±0.47 g water/g cocoa husk. Received: 19 December 1997 / Revised version: 27 February 1998     

Effects of transglutaminase on the rheological and Mixolab thermomechanical characteristics of oat dough

The effects of added transglutaminase (TG) on the rheological and thermal properties of oat dough were evaluated. Mixolab, rheometer, and differential scanning calorimetry (DSC) were used to analyse the oat dough for changes in thermomechanical, rheological, and thermal properties. TG had distinct effects on dough water absorption, modified viscoelastic behaviour, and enhanced thermal stability. The dough also exhibited a decrease in the number of free amino groups after TG treatment, confirming protein cross-linking catalysed by TG. Electrophoresis of TG-treated oat protein fractions using SDS–PAGE, which was also used to analyse the effects of TG on the protein fractions of oat flour; it showed that both globulin and avenin were good substrates for TG.     

Production of reduced‐fat Labneh cheese with inulin and β‐glucan fibre‐based fat replacer

The beneficial role of dietary fibre in human nutrition and effects of properties on fermented dairy products have led to a growing demand for the incorporation of novel fibre‐based fat replacers. The aim of the present work was to investigate the possibility of using inulin and oat‐based β‐glucan in Labneh cheese and to analyse the physico‐chemical, textural and sensory properties of the resulting product. The results showed that the textural and sensory properties of the cheese with addition of inulin increased at a 12% fat ratio. Overall, full‐fat and reduced‐fat Labneh cheeses were firmer and had better flavour than all the low‐fat cheeses. However, inulin and oat β‐glucan, as fermentable fibres, were also degraded as fermentable fibres to produce organic acids and had the potential for use as fat replacers in low‐fat dairy systems.     

Effects of fat level, tapioca starch and whey protein on frankfurters formulated with 5% and 12% fat

The effects of fat level (5% and 12%), tapioca starch and whey protein on the hydration/ binding properties, colour, textural and sensory characteristics of frankfurters were investigated. Decreasing the fat content increased cook loss and decreased emulsion stability and product lightness. Fat reduction increased smoke, spice and salt intensities and increased overall flavour intensity and juiciness. Texture profile analysis (TPA) indicated that fat reduction decreased gumminess and cohesiveness but the other parameters measured were unaffected. Addition of tapioca starch or whey protein reduced cook loss and increased emulsion stability. Whey protein did not effect the sensory characteristics but tapioca starch increased overall flavour intensity. Both ingredients increased hardness, adhesiveness, gumminess and chewiness as measured by TPA. Two-factor interactions between fat level and ingredient were observed for several parameters. The results indicate that both ingredients can partially offset some of the changes which occur in low-fat frankfurters when fat is replaced with added water and protein level is constant.     

Low-fat frankfurters formulated with a healthier lipid combination as functional ingredient: microstructure, lipid oxidation, nitrite content, microbiological changes and biogenic amine formation

Oil (healthier lipid combination of olive, linseed and fish oils)-in-water emulsions stabilized with different protein systems (prepared with sodium caseinate (SC), soy protein isolate (SPI), and microbial transglutaminase (MTG)) were used as pork backfat replacers in low-fat frankfurters. Microstructure, lipid oxidation, nitrite content, microbiological changes and biogenic amine formation of frankfurters were analyzed and found to be affected by the type of oil-in-water emulsion and by chilling storage (2° C, 41 days). Although the lipid oxidation levels attained were low, replacement of animal fat by healthier oil combinations in frankfurter formulation did promote a slight increase in lipid oxidation. Residual nitrite was affected (P < 0.05) by formulation and storage. Only 51-61% of the added nitrite was detectable in the product after processing and 17-46% at the end of storage. The microbial population was low in all formulations during chilling storage. Spermine was the most abundant amine (19-20 mg/kg), but similar in level to all samples.     

制粉方式对燕麦粉理化及面团特性的影响

以坝莜1号燕麦籽粒为原料,分别制粉获得炒制燕麦粉、燕麦片磨粉、超微燕麦粉3种燕麦面粉,并以实验室粉碎获得燕麦粉为对照,系统比较了不同处理获得燕麦粉的出粉率、理化指标以及面团特性。表明:炒制燕麦粉、燕麦片磨粉、超微燕麦粉的出粉率分别为79.4%、85.0%及95.0%。与对照燕麦粉相比,3种处理燕麦粉的脂肪含量均增加,而蛋白质含量、β-葡聚糖含量和灰分含量均减小。超微燕麦粉破损淀粉含量高;燕麦片磨粉色泽L值和a值最高,炒制燕麦粉的b值最大。峰值黏度、DSC热焓值从高到低依次为燕麦片磨粉、炒制燕麦粉和超微燕麦粉,且差异显著(P0.05)。扫描电镜观察发现燕麦片磨粉淀粉颗粒保留完整。3种燕麦粉的吸水率、峰值黏度、回生值、稳定时间都差异显著(P0.05),其中,炒制燕麦粉和超微燕麦粉吸水率高。总体而言,炒制燕麦粉各项指标较优。     

Use of image analysis to determine fat and connective tissue in salmon muscle

 An attempt was made to measure connective tissue and fat in salmon fillets using image analysis. Farmed salmon fillets were digitized by video camera and transferred to an image analysis program. A Laplace transformation was performed, and the image was segmented into different scales of grey. Particle analysis was applied to the binary pictures to calculate the percentage of white stripes in the total surface of the fillet, which were related to the percentage of connective tissue (CT) and fat. Although low correlation coefficients were obtained, it could be assumed that the video image analysis method is sensitive enough to detect great variations in fat content, which could prove useful in industrial applications. In contrast, CT was found to have less influence on the visual appraisal of the fillet surface. Received: 17 July 1998 / Revised version: 20 October 1998     

Effects of carrageenan and jackfruit puree on the texture of goat's milk Dadih using response surface methodology

Varying levels of carrageenan (0.1–0.7% w/v) and jackfruit puree (10–20% w/v) were incorporated into goat's milk Dadih (a traditional Malaysian dairy dessert), and texture attributes were obtained in the texture profile output. The desired texture was achieved by determining the optimum concentrations of carrageenan and jackfruit puree used, using response surface methodology. Hardness was significantly affected by both carrageenan and jackfruit puree concentration, while gumminess and elasticity were mainly affected by carrageenan. Graphical optimisation showed that Dadih with textural properties comparable with market could be obtained by incorporating 0.2% of carrageenan and 14.9% of jackfruit puree into the goat's milk Dadih.     

Whey protein concentrate/λ-carrageenan systems: Effect of processing parameters on the dynamics of gelation and gel properties

The thermal characteristics, dynamics of gelation and gel properties of commercial whey protein concentrate (WPC), WPC/λ-carrageenan (λ-C) mixtures (M) and WPC/λ-C spray-dried mixtures (DM) have been characterized. In a second stage, the effect of the gelling variables (T, pH, total solid content) on gelation and textural properties of DM was evaluated through a Doehlert uniform shell design.The presence of λ-C either in mixtures (M) or in DM promoted the WPC gelation at lower concentration (8%). M showed higher rates of formation and better gel properties (higher hardness, adhesiveness, springiness and cohesiveness) than DM.Nevertheless, when the effects of pH (6.0–7.0), heating temperature (75–90 °C) and total solid content (12–20 wt%) on gelation dynamics and gel properties of DM were studied, gels with a wide range of rheological and textural properties were obtained. While pH did not affect the gelation dynamics, it had some effect on rheological and textural properties. Total solid content and heating temperature were the most important variables for the dynamics of gelation (gelation rate (1/t_gel), gelation temperature (T_gel), rate constant of gel structure development (k_G), elastic modulus after cooling (G′_c) and textural parameters (hardness, springiness and cohesiveness).     

Seasonal changes in the fat composition of Lacha sheep's milk used for Idiazabal cheese manufacture

 The effect of the seasonality of lacha sheep's milk production on the milk-fat composition was studied. This raw milk is used to manufacture Idiazabal cheese, a typical product of the Basque Country of northern Spain. Milk samples were taken, prior to cheesemaking, from a refrigerated tank of mixed milk from different flocks in a cheese factory in February, April and June. The triglyceride and fatty acid composition of the milk were analysed. The results showed that the molecular characteristics of the milk-fat components, the degree of unsaturation and the chain length changed with the time of the year. The June milk had a higher content of unsaturated and long-chain fatty acids and triglycerides. The April and February milks were very similar, with a higher content of saturated and short-chain fatty acids and triglycerides. The differences in animal feeding are probably the most important factor affecting milk composition because in June flocks are fed mainly in natural pastures while in April and February the ewes are also fed additional commercial feeds. Idiazabal cheeses were considerably different from February to June, suggesting a relationship between the free fatty acid composition of the cheese, its sensorial properties and the fat composition of the raw milk used in cheesemaking. Received: 18 June 1999     

Studies on rats fed a dietary fibre preparation from sugar beet

 Groups of 15 female rats were fed ad libitum for 4 weeks with a standard diet containing 0, 2.5, 5 or 10% of a dietary fibre (DF) preparation made on a laboratory scale from sugar beet pulp. This preparation had a total DF content of 72.2%. Its major components were 36.7% cellulose, 16.9% pectin, 16.8% hemicelluloses (HC) and 11.0% protein. The DF preparation from sugar beet exhibited a water-binding capacity (WBC) of 8.9 g H₂O/g. As the proportion of DF preparation in the diet increased, up to 15.8% total DF, 4.6% cellulose and 1.9% pectin were found in the feeds. The WBC of the diets was estimated to be 1.4–2.9 g H₂O/g. At the end of the experiment, 20.3–64.1% total DF, 10.3–38.2% cellulose, 0.2–7.8% pectin, 4.3–9.2% HC pentoses and 4.3–10.3% HC hexoses were determined in caecum contents (ca. 0.6 g dry weight/rat). The following proportions were found in faeces (3rd week; 1.4–1.9 g dry weight/rat): 34.5–56.9% total DF, 19.5–36.1% cellulose, 6.4–8.4% HC pentoses, 7.4–8.3% HC hexoses. The WBC of faeces ranged from 3.7 g H₂O/g to 4.9 g H₂O/g. About 30–50% of the daily intake of DF appeared in the faeces. Higher amounts of total DF, pectin and HC pentoses were fermented by gastrointestinal microflora as the concentration of DF preparation from sugar beet in the diet increased. In addition, the fermentation of different DF components could be shown by the monosaccharide composition of caecum contents and faeces. Received: 21 October 1997     

Thermal properties of doughs formulated with enzymes and starters

 Thermal properties (gelatinization, amylose-lipid complex dissociation and amylopectin retrogradation) of bread samples formulated with two different quality wheat flours, two enzymes (α-amylase/pentosanase, lipase and their mixture), and three microbial sourdough starters were studied with a differential scanning calorimeter. The carbohydrases modified gelatinization temperature and enthalpy, whilst the lipase modified the amylose-lipid complex dissociation. The enthalpy of amylopectin retrogradation was significantly influenced only by the storage of breads. Second-order interactive effects of enzymes with flour or starter were found for gelatinization and/or amylose-lipid complex dissociation parameters. Some interesting relationships were observed between thermal and textural properties of fresh and stored breads. Received: 22 September 1998 / Revised version: 28 October 1998     

Flavor and texture characteristics of low fat ground beef patties formulated with whey protein concentrate

Low fat ground beef patties (10-11% fat), formulated with 10% water, 0.5% salt and 1-4% whey protein concentrate (WPC), were evaluated for cooking characteristics and compared with controls of higher fat content. A reduction in the fat level from 22 to 11% improved all cooking parameters with respect to better cooking yield (p < 0.01) and fat retention (p < 0.05), increased cooked moisture content (p < 0.05) as well as reduced shrinkage (p < 0.05). Texture profile analysis (TPA) showed an increase in chewiness for low fat samples over the high fat control, while hardness and springiness remained unaffected. Adding 10% water to the low fat meat did not change the cooking characteristics, except for a further increase in cooked moisture content (p < 0.05) and an increase in the value for springiness (p < 0.05). Addition of increasing levels of WPC with 10% water to low fat meat resulted in a linear increase (p < 0.05) in cooked yield with a linear decrease (p < 0.05) in shrinkage. The 4% WPC level produced the highest cooking yield (125% of the high fat control) and the least shrinkage (49% of the high fat control). Sensory analysis showed the 4% WPC level to be preferred over lower levels with respect to juiciness and overall acceptability. Addition of 0.3% of texture-modifying additives showed that calcium chloride and hydroxypropylmethylcellulose had a detrimental effect on yield and shrinkage, whereas the effect of tripolyphosphate (TPP) was positive (p < 0.05). Perception of juiciness and overall acceptability of formulated low fat products was significantly better (p < 0.05) with the addition of TPP (0.3%) and lactose (1.2%) to the WPC formulations. Fat levels (11, 18 and 22%) and lactose levels (0.24 and 1.2%) affected volatile components of the beef patties as measured by dynamic head space analysis. Ketones, i.e. 2-butanone, 2-pentanone and 3-hydroxy-2-butanone increased with an increase in fat content from 11 to 22% fat. Addition of WPC and lactose decreased the relative concentrations of pentane, hexane and heptane. The increase of lactose level in meat was accompanied by an increase in 4,4 diethyl-2-oxetanone and 2-methyl-butanal, two compounds that may originate from non-enzymatic browning of lactose.