Strategies to eliminate atypical flavours and aromas in sow loins. I. Optimization of sodium tripolyphosphate, sodium bicarbonate, and injection level

Sow meat has been identified to possess objectionable atypical aromas and flavors we have termed as “sow taint”. The objective of this study was to identify optimum concentrations of sodium bicarbonate (NaHCO₃), sodium tripolyphosphate (PO₄) and percentage marination solution that reduces or eliminates sow taint. Sow loins (N=20) with atypical aromas and flavors were treated with solutions containing sodium tripolyphosphate and sodium bicarbonate with concentrations ranging from 0.25 to 0.50% and 0.35 to 0.70 M, respectively. Injection levels (pump) ranged from 5 to 15% (wt./wt.). Marinated loin chops were evaluated for flavor and textural attributes by a trained sensory panel. Response surface methodology determined four optimum treatment combinations (15% pump, 0.5% PO₄, 0.70 M NaHCO₃; 15% pump, 0.25% PO₄, 0.70 M NaHCO₃; 15% pump, 0.25% PO₄, 0.35 M NaHCO₃; and 15% pump, 0.25% PO₄, 0.35 M NaHCO₃) that reduced (P<0.05) metallic aroma, metallic and sour aftertastes, and detectable connective tissue while improving (P<0.05) muscle fiber tenderness, juiciness, and overall tenderness.     

Sensory characteristics of Iberian dry-cured loins: Influence of crossbreeding and rearing system

The sensory characteristics of Iberian dry-cured loins and the influence of crossbreeding (pure Iberian - IB, Iberian female×Duroc male - IB×D and Duroc female×Iberian male - D×IB) and rearing system (outdoors fed on acorns and pasture - MON, indoors fed on concentrates high in oleic acid sunflower oil and supplemented with 250mg/kg of α-tocopherol acetate -HOVE- and indoors fed on control concentrates - CON) on sensory attributes were studied. Dry-cured loins from IB-MON and IB-HOVE pigs, which showed the highest intramuscular fat (IMF) content (p<0.01), reached higher scores for brightness, marbling traits (intensity, size and shape) and juiciness, and lower for hardness, dryness and fibrousness than loins from crossbred pigs (IB×D-HOVE, IB×D-CON and D×IB-HOVE). In fact, IMF content was positively linked to juiciness and marbling attributes and negatively to dryness, hardness and fibrousness, which was also observed in the principal component analysis (PCA). Neither the crossbreeding nor the rearing system seemed to influence odour, flavour and taste features. The PCA evidenced that dry-cured loins from IB-MON and IB-HOVE batches gathered together and were placed near to marbling attributes, juiciness and IMF content.     

Partial replacement of sodium chloride with potassium chloride in marinated rabbit meat

This study was aimed at evaluating the consequences of sodium chloride reduction by potassium chloride up to 50% on technological, sensorial and microbiological traits of marinated rabbit meat. In total, 226 rabbit loin meat samples were obtained and subjected to vacuum tumbling using solutions with different NaCl/KCl ratios. Replacing of sodium chloride up to 30% by potassium chloride did not change microbiological traits (total aerobic mesophilic and lactic acid bacteria maximum cell loads), sensorial acceptability (perceived saltiness and overall liking) and technological traits (pH, colour, texture, cooking loss and yield). Otherwise, reduction in sodium chloride to 50% significantly decreased perceived saltiness (4.15 vs. 4.73; P < 0.05) and reduced microbial shelf life by 1 day when compared to control, even if there was still no effect on technological traits. In conclusion, it is feasible imparting an added value for processed rabbit meat products by reduction in sodium content that could increase market interest.     

Phenolic content and antioxidant capacity versus consumer acceptance of soaked and vacuum impregnated frozen nectarines

Nectarines (Prunus persica L. cv. Maria Laura) were manually selected, cut in slices and divided into four groups: fresh, untreated frozen, soaked in osmotic solution and subsequently frozen, and vacuum impregnated (VI) and subsequently frozen. This investigation was focused on evaluation of consumer acceptance with respect to treated versus untreated frozen nectarine slices. In a preliminary acceptance test of untreated frozen nectarine slices, fruits were generally rejected on the basis of a darkened appearance and “oxidized” taste. These negative attributes were probably linked to the activity of polyphenol oxidase (PPO) and depletion of phenols due to cell rupture during freeze–thaw procedures. For these reasons, in order to evaluate the tendency of fruit to oxidation, several analyses were performed: the antioxidant capacity of phenolic fraction and the o-diphenol content were estimated by spectrophotometric assays, whereas the hydroxycinnamic acid (chlorogenic and neochlorogenic acids) composition was evaluated by high performance liquid chromatography (HPLC). Phenolic content and antioxidant capacity were found to correlate well with the acceptance level of frozen nectarine slices. In this regard a higher phenolic content associated with a higher acceptance level of nectarine samples.     

Development of a beef flavor lexicon and its application to compare the flavor profile and consumer acceptance of rib steaks from grass- or grain-fed cattle

Ten panelists were selected from the local community to develop a meat lexicon composed of 18 terms that describe flavor attributes found in red meats. This flavor lexicon was used to compare the flavor profile of meat from beef cattle finished on grass or grain. Steaks from grass-fed animals were significantly (P < 0.05) higher in barny, bitter, gamey, and grassy flavor, and lower in juicy and umami notes. Gamey, barny, bitter and grassy were some of the attributes inversely correlated to the degree of liking of the meat and therefore can be classified as “negative” attributes. Brothy, umami, roast beef, juicy, browned, fatty and salty are some of the attributes positively correlated to the degree of liking of beef and therefore can be identified as attributes that drive consumers’ acceptance. Steaks from grass-fed cattle were rated by consumers as slightly liked (6.08 on a 9-point scale), while steaks from grain-fed animals were rated as moderately liked (7.05 on a 9-point scale).     

Influence of freezing and thawing on the hydration characteristics,quality, and consumer acceptance of whole muscle beef injected with solutions of salt and phosphate

Effects of salt/phosphate injection level (112% or 125% pump), salt level (0.5% or 1.5% salt), and freezing/thawing on hydration characteristics, quality, and consumer acceptance of beef semitendinosus were investigated. All enhancement treatments decreased shear force by 25–35%, but negatively affected colour. Increased salt concentration yielded lower purge and cooking losses, and higher water holding capacity. The higher injection level reduced water binding properties, however, the loss in functionality with higher water addition was overcome with increased salt content. Freezing and subsequent thawing was generally detrimental to colour and water binding properties and tended to increase shear force. Freezing and subsequent thawing did not affect fluid release in steaks held for 1 day before analysis, but resulted in decreased water retention in samples held for 7 days. Holding vacuum packaged steaks for 7 days generally increased package purge and negatively affected colour parameters, although water binding characteristics were improved. Consumer panel results demonstrated a negative effect on juiciness and tenderness where meat subject to low salt/high injection was frozen then thawed – the low salt level was insufficient to maintain any positive effect of injection treatment. In general, salt/phosphate injection improved product acceptability and increased willingness to purchase.     

Influence of sodium chloride and sodium tripolyphosphate on the quality of UK-style grillsteaks: relationship to freezing point depression

Grillsteaks were prepared from lean beef flaked at –4°C and subsequently mixed at nominal temperatures of either –3°C or +1°C with each combination of five sodium chloride levels (0, 0.5, 1.0, 2.0 and 4.0%) and three levels of sodium tripolyphosphate (Na5P3O10) (0, 0.25 and 0.50%).
Sodium chloride was more effective than sodium tripolyphosphate in lowering the initial freezing point (ifp) of meat, as measured by differential scanning calorimetry which also showed that the freezing point depression was proportional to the solute concentration.
Cooking losses generally were lower with higher levels of sodium chloride and sodium tripolyphosphate, and when the meat was mixed at +1°C. It is argued that localized salt concentrations can influence product quality, as can the relative proportions of ice and water when meat is processed below the ifp.     

Short communication: Addition of varying amounts of sodium bicarbonate to colostrum replacer: effects on immunoglobulin G absorption and serum bicarbonate in neonatal calves

Fifty-two dairy calves were blocked by birth date and, within each block, randomly assigned to 1 of 4 treatments to investigate the effects of incremental levels of sodium bicarbonate (NaHCO₃) on IgG metabolism. Treatments were (1) colostrum replacer (CR) + 0 g of NaHCO₃ (control); (2) CR + 15 g of NaHCO₃; (3) CR + 30 g of NaHCO₃; or (4) CR + 45 g of NaHCO₃. Calves were fed colostrum replacer (>200 g of IgG) in one feeding within 45 min of birth (0 h) and 2 L of milk replacer at 12, 24, 36, and 48 h. Only calves born in calving pens from multiparous cows with no dystocia were used in this study. Blood samples were taken at 0, 6, 12, 24, and 48 h postpartum, and serum was analyzed for IgG using radial immunoassay and bicarbonate using spectrophotometry. Feeding increasing levels of sodium bicarbonate had negative linear effects on IgG concentration, IgG apparent efficiency of absorption, and IgG area under the curve, primarily due to the effect of the highest dose of NaHCO₃ (45 g). Sodium bicarbonate treatments had no effect on serum bicarbonate concentration. However, area under the curve of serum bicarbonate increased linearly with the amount of NaHCO₃ fed.     

Evaluation of Chinese tea by the electronic tongue: Correlation with sensory properties and classification according to geographical origin and grade level

Research was conducted to compare tea quality measured by a trained sensory panel and instrument analysis using a potentiometric sensor array. This array is formed by a set of non-specific all-solid-state potentiometric sensors and has been used in combination with principal component analysis (PCA) for the classification of tea samples from different geographical origins and quality grades. The method used to assess 10 sensory attributes in tea taste such as heavy flavor, thick flavor, sweet flavor, fresh flavor, mellow flavor, astringency, tenderness, stale flavor, purity and fired flavor were in accordance to the China National Institute of Standardization (CNIS) sensory profile test. The relationship between instrumental and sensory measurements of tea was also investigated. Results from these analyses demonstrate that the electronic tongue can be used to predict sensory characteristics and their relationship to the taste quality of tea measured by professional taster.     

Short communication: Addition of sodium bicarbonate to maternal colostrum: Effects on immunoglobuling absorption and hematocrit in neonatal calves

Twenty-six Holstein bull calves born from primiparous and multiparous cows without dystocia were assigned in a randomized complete block design to 1 of 2 treatments: pooled maternal colostrum (PMC) or PMC supplemented with 30g of sodium bicarbonate (NaHCO(3)). Calves were fed PMC from 9 different batches containing (mean ± SD) 82.05±8.45g/L of IgG. Calves were fed 2.68L of PMC at birth (referred to as 0h) and 1.32L of PMC 6h later. The total amount of IgG fed was 329.89±34.56g. Calves were fed 2L of milk replacer at 24, 36, and 48h postpartum. The addition of NaHCO(3) had no effect on IgG absorption. Serum IgG concentrations at 0, 6, 12, 24, and 48h postpartum were not different between calves supplemented with or without 30g of NaHCO(3) to colostrum. Area under the curve, apparent efficiency of absorption, and hematocrit were not affected by the NaHCO(3) treatment.     

An approach to the detection of synthetic milk in dairy milk: 3. Detection of vegetable oil and sodium bicarbonate

A high-performance thin layer chromatography (HPTLC) method for the detection of groundnut oil and palm oil, the main constituents of synthetic milk, was developed. The minimum detectable level of the oils was 80 mg/100 ml. The rosolic acid qualitative test was found to be sensitive enough to detect levels as low as 20 mg/100 ml sodium bicarbonate in milk.     

Contributions of non-volatile and volatile compounds to the umami taste and overall flavour of shiitake mushroom extracts and their application as flavour enhancers in cooked minced meat

Aqueous extracts of dried shiitake mushrooms (Lentinus edodes) were prepared as taste and flavour enhancers for meat formulations. Effects of time and temperature on the chemical and sensory properties of the extracts were examined. Extracts prepared at 70 °C had significantly higher concentrations (p < 0.001) of the savoury tasting 5′-ribonucleotides than those prepared at 22 °C but increasing the extraction time from 30 to 360 min only increased their recovery slightly (p = 0.053). In contrast, higher temperature extracts had considerably smaller concentrations of the major volatile compounds, such as lenthionine, 1-octen-3-ol, 1,3-dithiethane and dimethyl disulfide, because of loss through volatilisation.     

Effect of dietary supplementation with red wine extract or vitamin E,in combination with linseed and fish oil,on lamb meat quality

Thirty lambs were assigned to the following treatments: control diet (C) rich in omega-3 fatty acids; C plus 900 ppm red wine extract (RWE), or C plus 300 ppm vitamin E (VE). Oxidative stability and sensory properties of chops stored in MAP (70% O₂/30% CO₂) during 12 days were evaluated. Chops from the VE group showed lower lipid oxidation (p < 0.001) and protein carbonylation (p < 0.05), stable omega-3 fatty acids proportions and overall liking sensory scores (p < 0.05). Dietary RWE supplementation did not influence oxidative stability of chops, however levels of C20:5n-3 were greater (p < 0.05) and n-6/n-3 ratio (p < 0.01) was lower, relative to controls.     

Changes in microbial and postharvest quality of shiitake mushroom (Lentinus edodes) treated with chitosan-glucose complex coating under cold storage

The effect of chitosan, glucose and chitosan-glucose complex (CGC) on the microbial and postharvest quality of shiitake (Lentinus edodes) mushroom stored at 4 ± 1 °C for 16 days was investigated. Mushroom weight loss, respiration rate, firmness, ascorbic acid, total soluble solids, microbial and sensory quality were measured. The results indicate that treatment with CGC coating maintained tissue firmness, inhibited increase of respiration rate, reduced microorganism counts, e.g., pseudomonads, yeasts and moulds, compared to uncoated control mushroom. The efficiency was better than that of chitosan or glucose coating treatment. In addition, CGC coating also delayed changes in the ascorbic acid and soluble solids concentration. Sensory evaluation proved the efficacy of CGC coating by maintaining the overall quality of shiitake mushroom during the storage period. Our study suggests that CGC coating might be a promising candidate for maintaining shiitake mushroom quality and extending its postharvest life.     

Changing in processing yield and physical properties of frozen white shrimp (Penaeus vannamei) treated with lysine and sodium bicarbonate

The objective of this research was to investigate the phosphate alternative use of natural compound, lysine with sodium bicarbonate (NaHCO₃), at low concentration for freezing of white shrimp (Penaeus vannamei). Shrimp were treated with lysine, NaHCO₃ and lysine with NaHCO₃ at various concentrations and frozen in an air‐blast freezer. Thawing yield, cooking yield, colour, texture and nanostructure of the sample were studied compared to the control (nontreated sample) and sodium tri‐polyphosphate (STPP) treated one. Use of lysine/NaHCO₃ each at 1% (w/v) could improve water holding capacity (WHC) of the frozen shrimp, increasing cooking yield to 100.45% (w/w), comparable to the 101.73% (w/w) of STPP‐treated sample. The colour of the noncook‐thawed shrimp was also improved. Microstructure and lipid oxidation of the treated samples were also studied. The combination of lysine and NaHCO₃ indicated high potential use as phosphate alternative for frozen white shrimps.     

Correlations of trained panel sensory values of cooked pork with fatty acid composition,muscle fiber type,and pork quality characteristics in Berkshire pigs

The objective was to examine the relationship of trained panel sensory scores of cooked pork with fatty acid composition, muscle fiber type, and meat quality characteristics from Berkshire pigs. No or few associations were found between the panel sensory scores of cooked meat, especially tenderness attributes, and fatty acid composition; however, intramuscular fat content positively correlated with off-flavor score (r = 0.31). On the other hand, the morphological characteristics of muscle fibers were correlated with panel sensory values. Muscles with smaller cross-sectional area and higher density of fibers were more closely associated with softer, more tender panel scores and a lower number of chews than muscles with larger fiber area and lower density of fibers. The water holding capacity test of filter-paper fluid uptake was moderately correlated with panel scores of softness (r = 0.33), initial tenderness (r = 0.38), chewiness (r = 0.40), juiciness (r = − 0.27), flavor intensity (r = − 0.23), and off-flavor (r = 0.30). Panel sensory values of Berkshire pig meat was moderately related to postmortem meat quality, especially water holding capacity. A more thorough understanding of the relationships between fatty acid composition and muscle fiber type with palatability is needed.     

Addition of sodium bicarbonate to either 1 or 2 feedings of colostrum replacer: effect on uptake and rate of absorption of immunoglobulin G in neonatal calves

Forty Holstein dairy calves were blocked by birth date and sex, and randomly assigned to 1 of 4 treatments within each block to elucidate the effect of feeding regimen and sodium bicarbonate (NaHCO?) supplementation on absorption of IgG from colostrum replacer (CR). Calves received CR containing 191.4 g of IgG fed either in 1 feeding at 0 h (within 45 min of birth), with or without 30 g of NaHCO?, or in 2 feedings (127.6 g of IgG at 0 h, with or without 20 g of NaHCO?, and 63.8 g of IgG at 6 h, with or without 10 g of NaHCO?). The treatments were (1) 1 feeding of CR+0 g of NaHCO?; (2) 1 feeding of CR+30 g of NaHCO?; (3) 2 feedings of CR+0 g of NaHCO?; and (4) 2 feedings of CR+30 g total of NaHCO?. Only calves born with no dystocia were used on this study. Blood samples were taken at 0, 6, 12, 18, and 24h postpartum and were analyzed for IgG using a radial immunoassay. Results indicated that, individually, feeding regimen and NaHCO? treatments had no effect. However, the interaction was significant for 24-h IgG and area under the curve, and showed a trend for apparent efficiency of absorption. Absorption rate data indicated that, for calves fed within 45 min of birth, most IgG absorption occurred in the first 6 h after birth. From 6 to 12 h postpartum, IgG absorption started to decrease; however, IgG absorption remained higher for calves fed in a single feeding than in 2 feedings. These data indicated that NaHCO? may increase IgG absorption when calves are fed colostrum in a single feeding but is not beneficial when colostrum is fed in 2 feedings.     

Effect of an alkaline salt (papad khar) and its substitute (2:1 sodium carbonate:sodium bicarbonate) on acrylamide formation in papads

The formation of acrylamide in papads processed by flame roasting, frying and microwave roasting as a function of the alkaline salt, papad khar and its substitute, 2:1 sodium carbonate:sodium bicarbonate (w/w) at various concentrations was examined. Addition of papad khar and 2:1 sodium carbonate:sodium bicarbonate makes the product alkaline, which is known to be conducive for the formation of acrylamide. While a correlation was found between acrylamide content and pH with respect to fried and flame roasted papads, microwave roasting did not show any acrylamide formation at all the levels of alkaline salts tested in this study. Flame roasting generated higher levels of acrylamide as compared to frying. Use of microwave roasting is therefore recommended as a consumer-friendly, healthy and safe technology for processing papads.