Sodium chloride levels in comminuted chicken muscle in relation to processing characteristics and Fresnel reflectance detected with a polarimetric probe

Increasing NaCl from 0 to 2% in comminuted samples of chicken breast meat increased the resistance to compression of cooked samples (r=0.98, p < 0.001), increased water-holding capacity (r=0.95, p < 0.001), decreased cooking losses (r=−0.97, p < 0.001) and decreased paleness (L^*) before and after cooking (r = −0.96 and r=−0.99, respectively, p < 0.001). The decrease in paleness caused by NaCl was associated with an increase in the relative amount of reflected light maintaining its original plane of polarisation, so that NaCl% was correlated with an extinction coefficient for polarised light, r=0.91, p < 0.001. A possible explanation is that myofibrillar proteins may have been dissolved at high levels of NaCl, thus reducing light scattering by myofibrils and allowing more Fresnel reflectance to be detected.     

Determination of the caffeine contents of various food items within the Austrian market and validation of a caffeine assessment tool (CAT)

The caffeine content of 124 products, including coffee, coffee-based beverages, energy drinks, tea, colas, yoghurt and chocolate, were determined using RP-HPLC with UV detection after solid-phase extraction. Highest concentrations of caffeine were found for coffee prepared from pads (755?mg?l^?1) and regular filtered coffee (659?mg?l^?1). The total caffeine content of coffee and chocolate-based beverages was between 15?mg?l^?1 in chocolate milk and 448?mg?l^?1 in canned ice coffee. For energy drinks the caffeine content varied in a range from 266 to 340?mg?l^?1. Caffeine concentrations in tea and ice teas were between 13 and 183?mg?l^?1. Coffee-flavoured yoghurts ranged from 33 to 48?mg?kg^?1. The caffeine concentration in chocolate and chocolate bars was between 17?mg?kg^?1 in whole milk chocolate and 551?mg?kg^?1 in a chocolate with coffee filling. A caffeine assessment tool was developed and validated by a 3-day dietary record (r ^2?=?0.817, p?<?0.01) using these analytical data and caffeine saliva concentrations (r ^2?=?0.427, p?<?0.01).     

Caffeine metabolism rate influences coffee perception,preferences and intake

Several factors – genetic, demographic and environmental – contribute to individual differences in sensitivity to the pharmacological effects of caffeine. Caffeine metabolism influences coffee consumption, but its effect on bitterness perception in, and preference for, coffee is unknown.This study explores the possible relationship between caffeine metabolism rate and coffee preferences and consumption habits. In addition, the extent to which caffeine metabolism interacted with variations in bitterness perception was investigated. Caffeine metabolism rate was assayed by competitive immuno-enzymatic assay in one-hundred thirty-five coffee consumers who provided saliva samples after 12 h caffeine abstinence and at 30 and 90 min after ingestion of caffeine (100 mg). A caffeine metabolism index (CmI) was computed as the ratio between the amount of residual caffeine in saliva 60 min after the adsorption peak and the amount of caffeine at the adsorption peak corrected with the baseline. Ninety-one subjects were selected to investigate the relationships between inter-individual variation in caffeine metabolism, bitterness perception and coffee preference. Subjects rated liking for, and sourness, bitterness and astringency of, six unsweetened and freely sweetened coffee samples varying in roasting degree, caffeine content and bitterness. They also rated the bitterness of six caffeine and six quinine (equi-intense) solutions. Finally, subjects choose coffee to drink on the basis of a label (strong vs balanced flavor) both after caffeine abstinence and after no restrictions on caffeine intake. The CmI was strongly associated with the frequency of daily coffee consumption. Subjects with lower CmI gave higher bitterness ratings than other subjects for both coffee and caffeine solutions, but not for quinine solutions. They also added more sugar to the coffee samples. Following caffeine abstinence, all subjects chose the “strong flavor” coffee, while without caffeine restrictions, subjects with lower CmI preferentially tended to choose the “balanced flavor” coffee. These results provide the first link between caffeine metabolism and bitterness perception, and to the use of sugar to modify coffee bitterness.     

Infant formula iron dialysability related to other nutrients

The dialysable iron in relation to total iron, to protein sources, to calcium, magnesium, copper, zinc, and vitamin C of 17 infant formulas, from four different multinational companies were analyzed. Total iron, calcium, magnesium, copper, and zinc were determined by atomic absorption spectrophotometry. The dialysable iron was determined. The considered vitamin C concentration was that declared on the labels. There was no significant statistical relationship between total iron and dialysable iron (P = 0.54, r = 0.09) when considered separately. When analyzed considering protein sources, this relationship was shown to be inversely proportional to protein hydrolysate (P = 0.03, r = −0.72), and soy protein (P = 0.02, r = −0.93). The percentage of dialysable iron was significantly greater from the protein hydrolysate (P < 0.01). The dialysable iron showed a negative correlation with calcium (P < 0.05, r = −0.61). In conclusion, the infant formulas whose protein sources are casein and casein plus whey protein should present Ca:Fe and Fe:vitamin C ratios that allow considerable iron dialysability.     

Quality and shelf life evaluation of fermented sausages of buffalo meat with different levels of heart and fat

Investigations were carried to study the effect of heart incorporation (0%, 15% and 20%) and increasing levels of fat (20% and 25%) on physicochemical (pH, moisture content and thiobarbituric acid, TBA number) and microbiological (total plate count and yeast and mold count) quality and shelf life of semi dry sausages of buffalo meat during refrigerated storage (4 °C). Different levels of fat significantly (p < 0.05) increased the pH of the sausage samples. However different levels of heart incorporation did not significantly (p < 0.05) affect pH, moisture content and TBA number of sausage samples. Fresh samples had pH, moisture content and TBA number in the range of 5.15–5.28, 42.4–47.4% and 0.073–0.134 respectively. Refrigerated storage significantly (p < 0.05) increased TBA number of control samples while storage did not significantly (p < 0.05) increase the TBA number of sodium ascorbate (SA) treated samples. Total plate counts of twelve sausage samples were f under the TFTC (too few to count) limit at the initial stage. Incorporation of different levels of heart and also increasing levels of fat did not significantly (p < 0.05) increase the log TPC/g values. Yeast and molds were not detected in twelve samples of semi dry fermented sausages in their fresh condition. Storage revealed that there was a consistent decrease in pH, and moisture content. Refrigerated storage significantly (p < 0.05) reduced both pH and moisture contents. TBA number and total plate counts and yeast and mold counts of controls were found to increase significantly (p < 0.05) during refrigerated storage. However, in SA treated sausage, only TPC and yeast and mold count significantly (p < 0.05) increased during refrigerated storage. Shelf life of the sausages was found to be 60 days under refrigerated storage (4 °C).     

Meat quality characteristics of springbok (Antidorcas marsupialis). 3: Fatty acid composition as influenced by age, gender and production region

The effects of age, gender and production region on the fatty acid composition of springbok Musculus longissimus dorsi (LD) were investigated. The major fatty acid of the LD muscle was stearic acid (C18:0), which contributed 23.92–27.02%. Oleic acid (C18:1) represented the largest component (16.33–20.45%) of the mono-unsaturated fatty acids (MUFA). The major n − 6 polyunsaturated fatty acid (PUFA) was C18:2n − 6, which formed 18.77–21.62%, whereas C18:3n − 3 (3.33–4.00%) was the most abundant n − 3 PUFA. The n − 6:n − 3 ratio of the meat varied from 3.02 to 3.35, with an average ratio of 3.2. Polyunsaturated to saturated (P:S) ratios varied between 0.96 and 1.18 and averaged at 1.06. Total MUFA was found to be higher (P < 0.05) in males (20.99%) than females (16.67%). The cholesterol content of the meat varied from 54.45 to 59.34 mg/100 g muscle. Linear correlations between the fatty acid and the intramuscular fat (IMF) content indicated a significant increase in certain saturated and mono-unsaturated fatty acids with increasing IMF content of the meat.     

Genotype and gender differences in carnosine extracts and antioxidant activities of chicken breast and thigh meats

The aim of this work was to investigate the effects of genotypes and gender of chickens on carnosine contents and their antioxidant activities. The carnosine content of fresh meat from Thai indigenous and hybrid native chickens differed between breeds (p < 0.01) and genders (p < 0.01). Regardless of these differences, breast meat contained 2–4-fold higher carnosine than thigh meat. After water and heat extraction at 80 °C and ultrafiltration, the carnosine content of meat extracts had the same distribution as in fresh meat. No relationship between total iron and carnosine content on antioxidant activity of the extract was detected. However, when compared in the extracts on the basis of mM carnosine in oxidation system, the extracts of chicken meat showed greater antioxidant activity than pure carnosine (p < 0.05). Furthermore, at equal concentrations, thigh meat extract had higher effective inhibiting ability than breast extract.     

Fatty acids in muscles and liver of Tunisian wild and farmed gilthead sea bream, Sparus aurata

The total fat content and the fatty acids profile were analysed in the dorsal and ventral muscles and in the liver from wild and farmed gilthead sea bream (Sparus aurata). The amount of fish lipid was higher in farmed than in wild fish in all studied samples and the highest level of all was observed in liver. It was noted that, among all the samples studied for saturated fatty acids (SFA) and Monounsaturated fatty acids (MUFA), whether farmed or wild, palmitic (C16:0) and oleic (C18:1 n − 9) acids were the principal saturated and monounsaturated fatty acids. The results showed that farmed fish contained a higher level of n − 3 polyunsaturated fatty acids (PUFA), particularly docosahexaenoic acids (DHA) and eicosapentaenoic acids (EPA), whereas wild fish contained a higher level of n − 6 PUFA. Arachidonic acid (C20:4 n − 6) was the primary n − 6 PUFA in wild fish whereas in farmed fish, linoleic acid (C18:2 n − 6) was the major n − 6 PUFA. Farmed fish were characterized by higher n − 3/n − 6 ratio for all samples studied, due to the abundance of n − 3 PUFA, particularly DHA.     

Sodium lactate influences myoglobin redox stability in vitro

Injection-enhancement of beef with lactate improves color stability; however, the mechanism is unclear. Thus, our objectives were to assess the effects of sodium lactate on equine myoglobin redox stability in vitro. Oxymyoglobin at pH 5.6 (50 mM sodium citrate) and pH 7.4 (50 mM sodium phosphate) was incubated at 4 °C with lactate (0, 5, 10, 100, or 200 mM) and myoglobin redox form was determined using absorbance spectra. Metmyoglobin formation at pH 5.6 and 7.4 was significantly (P < 0.05) decreased by lactate at concentrations of 100 and 200 mM. In general, increasing lactate concentration from 100 to 200 mM increased (P < 0.05) oxymyoglobin redox stability. This effect of lactate on myoglobin redox stability could be partially responsible for the improved color stability associated with lactate injection-enhanced beef products. Further work should determine the effect of lactate on beef myoglobin.     

Caffeine daily intake from dietary sources in Brazil

A survey on the potential intake of caffeine was carried out in Campinas, SP, Brazil, in the summer of 1993. The survey was based on a representative sample of 600 individuals, 9-80 years old, who were asked about their habitual usage of coffee, tea, chocolate products and carbonated beverages. Caffeine levels in the products were determined by high performance liquid chromatography with a UV-visible detector at 254 nm. Individual daily intakes (mg/kg b.w.) of caffeine were calculated from the consumption data generated by the survey and the caffeine content of the analysed products. Of all those interviewed, 81% consumed soft drinks regularly, 75% coffee, 65% chocolate products and 37% tea. Of the analysed products, coffee showed the highest amount of caffeine. The average and median potential daily intake of caffeine by the studied population were, respectively, 2.74 and 1.85mg/kg b.w. Coffee, tea, chocolate products and carbonated beverages accounted for median individual daily intakes of 1.90, 0.32, 0.19, and 0.19mg/kg b.w., respectively. These data show that coffee is the most important vehicle for caffeine intake within the studied population.     

Characterisation of intramuscular, intermuscular and subcutaneous adipose tissues in yearling bulls of different genetic groups

Fatty acid (FA) composition of intramuscular (IM, Longissimus thoracis muscle), intermuscular (IT) and subcutaneous (SC) fat of one hundred intensively fed yearling bulls with different propensities to fatten were studied. Meat samples were collected from Asturiana de los Valles bulls with different genotypes with respect to the myostatin gene (mh/mh n = 24, mh/+ n = 26 and +/+ n = 25) and from Asturiana de la Montaña (n = 25) bulls lacking the mutation responsible for double muscling and characterised by small to medium-frame size adapted to less favoured mountain areas. FA profiles were expressed as percentages of total FA (g/100 g of total FA) and organised into groups (saturated (SFA), branched (BFA), monounsaturated (MUFA), C18:1trans, polyunsaturated (PUFA), n − 6, n − 3, conjugated linoleic acids (CLA), unsaturated (UFA)) and ratios (MUFA/SFA (M/S), PUFA/SFA (P/S), UFA/SFA (U/S), n − 6/n − 3).

The IT depot was the most saturated and SC depot contained the most monounsaturated FAs, while IM fat had the most polyunsaturated FAs. IM fat showed the highest P/S ratio and for the n − 6/n − 3 ratio there were no significant differences between adipose tissue depots.

In general, genotype effects were more pronounced in IM and SC fat profiles compared to the IT depot, for which no significant differences between genotypes were found in SFA, PUFA (including n − 6 and n − 3), UFA and most of the ratios. IM fat of mh/mh animals had the highest content of PUFA and thus the highest P/S ratio. Accordingly, the presence of the gene causing double muscling influenced the tendency to deposit carcass fat and its FA composition, mainly in IM fat. In general, when carcass fat decreased, SFA content decreased while PUFA and UFA contents increased due to the changes in their percentages.     

Fatty acids and tocopherol levels in M. Longissimus dorsi of beef cattle in Sweden - A comparison between seasonal diets

This study investigated the influence of Swedish outdoor feeding systems on the fatty acid composition and tocopherol content of M. Longissimus dorsi from beef. Dietary effects of pasture (PA), silage, and silage supplemented with grain (SIG) were compared. Each dietary group consisted of six animals. Higher levels (P < 0.05) of polyunsaturated fatty acids (PUFA) were found in the PA treatment. The n − 6/n − 3 fatty acid ratio of total lipids in the muscle tissue was in the range 1.2–1.5. The SIG treatment increased the n − 6/n − 3 ratio and decreased the total PUFA content of muscle tissue. The lipid class composition and the content of -tocopherol in the meat showed no differences among treatments.     

Rejection Thresholds in Chocolate Milk: Evidence for Segmentation

Bitterness is generally considered a negative attribute in food, yet many individuals enjoy some bitterness in products like coffee or chocolate. In chocolate, bitterness arises from naturally occurring alkaloids and phenolics found in cacao. Fermentation and roasting help develop typical chocolate flavor and reduce the intense bitterness of raw cacao by modifying these bitter compounds. As it becomes increasingly common to fortify chocolate with `raw' cacao to increase the amount of healthful phytonutrients, it is important to identify the point at which the concentration of bitter compounds becomes objectionable, even to those who enjoy some bitterness. Classical threshold methods focus on the presence or absence of a sensation rather than acceptability or hedonics. A new alternative, the rejection threshold, was recently described in the literature. Here, we sought to quantify and compare differences in Rejection Thresholds (RjT) and Detection Thresholds (DT) in chocolate milk spiked with a food safe bitterant (sucrose octaacetate). In experiment 1, a series of paired preference tests was used to estimate the RjT for bitterness in chocolate milk. In a new group of participants (experiment 2), we determined the RjT and DT using the forced choice ascending method of limits. In both studies, participants were segmented on the basis of self-declared preference for milk or dark solid chocolate. Based on sigmoid fits of the indifference-preference function, the RjT was ~2.3 times higher for those preferring dark chocolate than the RjT for those preferring milk chocolate in both experiments. In contrast, the DT for both groups was functionally identical, suggesting that differential effects of bitterness on liking of chocolate products are not based on the ability to detect bitterness in these products.     

Meat quality characteristics of springbok (Antidorcas marsupialis). 1: Physical meat attributes as influenced by age, gender and production region

Springbok is the most extensively cropped game species in South Africa. The effects of age (adult, sub-adult, lamb), gender and production region on the physical attributes (pH₂₄, cooking and drip loss, Warner Bratzler shear force and colour) were determined using samples of the M. longissimus dorsi (LD) muscles of 166 springbok. Stressed animals had a higher (P < 0.05) pH₂₄ (6.3 ± 0.07), as observed in the meat originating from the Caledon region. This meat had lower (P < 0.05) cooking loss (27.2 ± 0.62%) and drip loss (1.8 ± 0.08%) values in comparison to meat originating from the other regions. Inverse correlations were noted between pH₂₄ and drip loss (r = −0.26, P < 0.01) and cooking loss (r = −0.42, P < 0.001). Shear force values (kg/1.27 cm diameter) correlated positively (r = 0.25, P < 0.01) with pH₂₄. Age-related effects on tenderness were small in comparison with pH₂₄ effects. CIELab colorimetric values were typical of game meat and venison (L^* < 40, high a^* and low b^* values). It was noted that pH₂₄ correlated negatively (r = −0.51, P < 0.001) and positively (r = 0.33, P < 0.001) with the hue-angle and the chroma value of colour, respectively. Springbok originating from Caledon had a significantly (P < 0.05) higher a^* value, indicating meat to be more red with higher colour saturation.     

Augmented postmortem glycolysis does not occur early postmortem in AMPKγ3-mutated porcine muscle of halothane positive pigs

The objective of this study was to determine the effects of the halothane (HAL) and Rendement Napole (RN) genes on the rate-limiting reactions of glycolysis and their relationship to pork quality development. Samples were collected from the longissimus muscle at 0, 30, 60, and 120 min and 24 h postmortem from homozygous HAL and RN pigs (NN/rn⁺rn⁺, NN/RN⁻RN⁻, nn/rn⁺rn⁺, nn/RN⁻RN⁻). Muscle pH was recorded at 0, 15, and 45 min, and 24 h postmortem. HAL mutants, compared with HAL normal, had lower (P < 0.05) ATP concentrations at 0 and 30 min, lower (P < 0.05) pH at 45 min, and hastened glycogen degradation and lactate accumulation in the first 120 min postmortem (HAL × time, P < 0.0001). RN mutants had greater (P < 0.0001) glycolytic potentials than RN normal, and lower (P < 0.05) 24 h pH compared with the normal genotype, but not the HAL mutant genotype. The HAL mutation negatively affected (P < 0.05) L*, b* and color scores whereas both HAL and RN mutations independently decreased (P < 0.05) firmness, marbling and water holding capacity. RN mutant genotypes had higher (P < 0.0001) phosphocreatine concentrations than other genotypes at 0 min. Compared with HAL normal, HAL mutants had elevated (P < 0.05) muscle glucose concentrations at 30, 60, and 120 min, and 24 h. RN mutants had higher (P < 0.05) glucose levels than RN normal after 60 min. Glucose-6-phosphate (G6P) concentrations decreased (P < 0.05) during the first hour postmortem except in HAL/RN mutants, which had higher (P < 0.01) G6P concentrations than all other genotypes at 30 min. From 60 min to 24 h postmortem, G6P increased (P < 0.05) in HAL normal genotypes. Altogether, these data show that elevated muscle glycogen content does not further aggravate rapid early postmortem metabolism.     

Drip loss of case-ready meat and of premium cuts and their associations with earlier measured sample drip loss, meat quality and carcass traits in pigs

Drip loss of 374 samples taken from porcine M. longissimus dorsi and M. semimembranosus was measured by using the “bag method” (BM), EZ-DripLoss (EZ-DL) from premium cuts (PC) and in retail tray (case-ready meat; CRM). This provided a comparison between these methods and their relationships to other meat quality and carcass traits. Samples were prepared at 24 h post-mortem (pm) and were measured 24 and 48 h after preparation (at 48 and 72 h pm) using the BM and after 48 h (at 72 h pm) with the EZ-DL and PC. Drip loss of meat kept in retail trays was measured after 7 days (CRM₇) and daily within a week (CRM_1–7). Average drip loss was 1.80% and 3.10% using the BM after 24 and 48 h, respectively. EZ-DL and CRM₇ showed higher drip losses of 4.71% and 4.00%. Daily loss of CRM_1–7 showed a concavely shaped curve and increased from 1.57% to 5.64% after 7 days. High correlations were obtained between drip loss of CRM₇ and BM (r = 0.88) or the EZ-DL (r = 0.91). The development of drip loss in case-ready meat fitted by linear-quadratic regression (y = 0.439 + 1.245x − 0.072x²) showed that high drip loss measured earlier by bag and EZ-DripLoss methods was highly associated with a high intercept (r = 0.63–0.72), a high linear increase (r = 0.77–0.81), but larger decrease in increments (r = −0.82 to −0.86) during weekly stored meat in retail trays as supplied at consumer level. Because the positive linear regression coefficient was substantially higher than the negative quadratic regression coefficient, the development of drip loss is mainly dependent on the initial drip loss. Therefore, animals with high drip loss within 72 h post-mortem also showed undesirable high drip loss curves over the entire retail period. Relationships between drip loss and other meat quality traits were similar for BM, EZ-DL and CRM₇. Of these the correlation between pH₂₄ and drip loss was highest with r = −0.54, −0.49 and −0.47 for BM, EZ-DL and CRMH₇, respectively. Interestingly, a correlation of r = −0.35 between blood pH value and CRML₇ was obtained. Carcass traits such as loin, ham, shoulder, belly weight or loin eye area showed only marginal correlations to drip loss. In conclusion, EZ-DL was the most appropriate method to predict drip loss of case-ready meat in retail trays and its development during a 7 day storage period.     

Analysis of potential lard adulteration in chocolate and chocolate products using Fourier transform infrared spectroscopy

Fourier transform infrared (FTIR) spectroscopy, in combination with attenuated total reflectance (ATR) and partial least square (PLS) regression, was used to detect the presence of lard in chocolate formulation. The spectral bands associated with lard, cocoa butter and their blends (ranging from 0% to 15% of lard in cocoa butter) were recorded, interpreted and identified. A semi-quantitative approach is proposed to measure the percent of lard in blends on the basis of spectral data at the frequency region 4000–650 cm⁻¹, using the equation y = 0.9225x + 0.5539. The coefficient of determination (R²) was 0.9872 with a standard error (SE) of 1.305. In this paper, the potential of FTIR spectroscopy as a rapid analytical tool for the quantitative determination of adulterants especially lard, in chocolate, is demonstrated.     

Chemical, physical and sensory properties of meat from pure and crossbred Podolian bulls at different ageing times

The present study aimed to investigate the effect of crossbreeding with Limousine sires on fatty acid profile, physical and sensory properties of meat produced by Podolian young bulls. Polyunsaturated fatty acid content was influenced by crossbreeding (P < 0.01) with Podolian bulls (P) producing beef characterised by a higher level of unsaturation in comparison with crossbred animals (LP). As a consequence, P/S ratio was significantly higher in meat produced by P animals than LP (P < 0.01). P animals had higher linoleic (P < 0.05), linolenic (P < 0.05), EPA (P < 0.05) and DHA acids (P < 0.001) levels than LP subjects. No breed effect was observed for the ratio n − 6/n − 3 (P > 0.05). WBS force of LD was significantly lower in meat from crossbred subjects (P < 0.05). Both crossbreeding with Limousine and extension of ageing from 2 to 7 days improved LD tenderness as assessed by panel taste (P < 0.001).     

Effects of ultrafiltration of whole milk on some properties of spray-dried milk powders

The objective was to produce spray-dried milk powders for assessment subsequently in chocolate. Milks were ultrafiltered to increase their protein content (3.08–5.33 g 100 g⁻¹), concentrated to different solids levels (42.8–52.3 g 100 g⁻¹) and spray-dried to produce powders (26–59 g 100 g⁻¹ fat). The relationships between the milk protein content, concentrate viscosity and some powder properties were quantified. The free-fat content of the powders increased linearly to 74 g 100 g⁻¹ fat with milk protein content for 26 and 40 g 100 g⁻¹ fat powders. The particle size and moisture content of the powders increased linearly with concentrate viscosity for 26 g 100 g⁻¹ fat powders. Differences between the control and ultrafiltration-treated milk powders were explained. The free-fat content and the particle size increased with the fat content of the control powders. The vacuole volume of the powders was inversely more related to the free-fat content than to the fat content of the control powders.