Instrumental Color Parameters Research Articles

Oil-in-water emulsion loaded with optimized antioxidant blend improved the shelf-life of trout (Oncorhynchus mykiss) fillets: a study with simplex-centroid design.

This study aimed to obtain optimized mixture with three essential oils (EOs) for maximum antioxidant activity through the augmented simplex-centroid mixture design and evaluate the effect of this optimized blend on total aerobic psychrotrophic count (TAPC), lipid and protein oxidation, instrumental color parameters and texture profile in rainbow trout fillets at refrigerated storage for nine days. Considering the DPPH and FRAP assays, the ideal EO blend was 66% lemongrass and 34% oregano. During refrigerated storage, this blend at 2000ppm was equally effective as BHT (100ppm) (p > 0.05), mitigating the discoloration (a* and b*), lipid, and protein oxidation in 38.83%, 12.95%, 76.13%, and 35.13%, respectively, besides shows greater effectiveness for preserving texture changes (p < 0.05) and extending the shelf life in 13h. The lemongrass + oregano EO blend reveals a promising natural alternative to enhance the quality of rainbow trout fillets under refrigerated storage. Furthermore, the multiresponse optimization showed to be a strong ally in enabling the use of these EOs by food industries.

A New Advancement in Germination Biotechnology of Purple Creole Corn: Bioactive Compounds and In Situ Enzyme Activity for Water-Soluble Extract and Pan Bread.

Germination is a simple and cost-effective technology that enhances the technological, sensory, and nutritional potential of grains, making them more attractive for use in the food industry. Germinating indigenous seeds is an alternative to increase noticeability and add value to these grains, which hold social and economic significance in the regions where they are cultivated, such as creole purple pericarp corn (PPCC) from the Couto Magalhães de Minas region in Brazil. This study aimed to optimize the germination parameters of time (24-96 h) and temperature (18-32 °C) for PPCC to produce water-soluble extracts and bread. Endogenous enzymes resulting from the germination process significantly enhanced (p < 0.10) the technological (total reducing sugars, total soluble solids, and soluble proteins) and biological properties (γ-aminobutyric acid, total soluble phenolic compounds, and antioxidant capacity) of the water-soluble extracts. The optimum point for obtaining the extracts was found to be at 85.3 h at 30.46 °C (with desirability of 90.42%), and this was statistically validated. The incorporation of germinated PPCC flours into bread was also promising (p < 0.10) and had a positive impact on the dough property (dough volume increase) and the final product, especially in terms of instrumental texture (springiness, cohesiveness, gumminess, chewiness, and resilience), resulting in a softer texture (lower firmness and hardness). The addition of PPCC flours did not alter instrumental color parameters, which may lead to greater consumer acceptance due to imperceptible differences in color to untrained individuals, with the optimized point at 96 h at 29.34 °C, with a desirability of 92.60%. Therefore, germinated PPCC shows promise for use as a base for obtaining water-soluble extracts and in bread as a replacement for commercial flour improvers, while also adding value to a raw material that is part of the local culture and agrobiodiversity.

Optimizing UVC-LED application to improve the shelf life of vacuum-packed refrigerated stored Nile tilapia (Oreochromis niloticus) fillets.

Although ultraviolet-C light-emitting diode (UVC-LED) has proven antimicrobial effectiveness doses needed to reach it cause adverse effects on the physicochemical quality of fish, and thus, optimization studies are crucial to boost its industrial application. This study aimed to identify optimal UVC-LED conditions for maximum shelf life extension with the least possible quality changes of refrigerated stored tilapia fillets from a central composite rotatable design (CCRD). UVC-LED powers (1, 1.38, and 1.58mW/cm2 ) and times (500, 1800, and 2700s) were set on the CCRD, which generated 11 treatments, including three replicate experiments. Treatments were analyzed for total aerobic psychrotrophic count, lipid oxidation, instrumental color, and texture parameters on days 0, 2, 4, 7, 11, and 14. The UVC-LED affected shelf life and physicochemical parameters in a nonlinear fashion. UVC-LED-treated fish had increased shelf life by 2.80-4.76 days and increase or decrease in lipid oxidation (0.025-0.276mg of malondialdehyde [MDA]/kg), total color change (∆E=3.47-9.06), and hardness (1.31-8.51N) over the refrigerated storage depending on specific UVC-LED conditions applied. The optimal UVC-LED condition was 0.97mW/cm2 with 2503.6s (2428.50mJ/cm2 ), which increased the fillet's shelf life by 2.5-fold (2 days) while maintaining quality closer to the original throughout refrigerated storage, resulting in ∆E<5, an increase of only 0.05mg of MDA/kg, and preservation of the decrease in hardness by 3.38N compared to its control counterparts. Therefore, it represents an eco-friendly technology that can easily scaled industrially to enhance the sustainable fish production chain. PRACTICAL APPLICATION: The high fish perishability is a global concern due to food safety risks and waste generation impacting the environment adversely, especially nowadays, where fish production and consumption have increased, and there are more evident efforts to sustainable production. UVC-LED is an eco-friendly technology with proven antimicrobial effectiveness but doses needed to reach this effect enhance oxidative degradation. Despite that, optimization studies concerning the maximum shelf life extension while retaining the physicochemical quality of refrigerated stored fish are a gap in the literature and a barrier to its industrial application. Our findings are helpful in sustainably enhancing the fish production chain.

Gelatin-sodium alginate packaging film with date pits extract: An eco-friendly packaging for extending raw minced beef shelf life

Gelatin-sodium alginate-based active packaging films were formulated by including date pits extracts (DPE), as bioactive compound, in raw minced beef meat packaging. The DPE effects at 0.37, 0.75 and 1.5% (w/w, DPE/ gelatin-sodium alginate) on physical, optical, antioxidant and antibacterial properties of established films were assessed. Findings showed that film lightness decreased with the incorporation of DPE. Physical, antioxidant and anti-food-borne pathogens capacities were enhanced by increasing DPE concentration in the films. For 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), the films with 1.5% DPE had the greatest levels (94 and 88%, respectively). DPE films (1.5%) also exhibited the highest anti-Listeria moncytogenes activity, with an inhibition zone of 25 mm. Moreover, during 14 days at 4 °C, the bio-preservative impact of gelatin-sodium alginate film impregnated with DPE at three levels on microbial, chemical, and sensory characteristics of meat beef samples was evaluated. By the end of the storage, DPE at 1.5% enhanced the instrumental color, delayed chemical oxidation and improved sensory traits. By chemometric techniques (principal component analysis (PCA) and heat maps), all data allowed to obtain helpful information by segregating all the samples at each storage time. PCA and heat maps could connect oxidative chemical changes, instrumental color parameters, and microbiological properties to sensory attributes. These data offer an approach to well interpreting the sensory quality and how they are affected by chemical and microbiological changes in the studied meat samples. Our findings indicated the potential of the gelatin-sodium alginate film incorporated with DPE for enhancing meat safety and quality.

Comparative study on the effects of sous-vide, microwave cooking, and stewing on functional properties and sensory quality of goose meat

The effect of sous-vide (SV), microwave (M) cooking, and stewing (S) on selected functional properties of goose meat were investigated in this study. It was measured cooking loss (CL), texture and color parameters, and sensory evaluation was carried out. The material were 96 breast muscles (BM, n=48 with skin and subcutaneous fat and n=48 without skin) from 17-wk-old "Polish oat geese." The kind of heat treatment and the type of goose meat and interaction the type of meat×heat treatment affected the amount of CL. The lowest value of CL was stated for SV samples. The meat with skin was characterized by a lower shear force value (SF), hardness, gumminess, and chewiness than samples without skin for all cooking methods. There were no differences in SF value for M and S samples with skin. The S samples characterized by the highest value of SF, hardness and the SV meat by the lowest for both kind of meat. The M samples characterized by the higher value of cohesiveness, gumminess and chewiness compare to SV and S meat. All instrumental color parameters were significantly affected by cooking technology (P=0.001). There were differences in color lightness (L*) of investigated cooked samples. The SV meat had the highest value of L* parameter and was characterized by a lighter color among others. The highest decrease in a* value was stated for S and lowest for SV meat. The SV showed more intense red color than remaining samples. The a* value decreased and b* parameter increases with an increase the heat treatment temperature. The value of b* was higher in S (about 100°C) samples than in raw meat and processed by SV (70°C). From consumer point of view the best color had goose breast muscles subjected to SV process. Considering all tested sensory features, the overall palatability of SV goose samples was rated as excellent, S as very good and M as good.

Effect of feeding olive pomace acid oil on pork lipid composition, oxidative stability, colour, and sensory acceptance.

One of the targets of the meat industry is to reduce production costs and to increase the sustainability of the food chain, which has driven the attention towards the use of by-products as feed ingredients. Acid oils are fat by-products coming from the chemical refining process of edible oils, with a high energy value and that are approved as feed ingredients in the European Union. However, meat producers are hesitant to utilise them due to their varying composition and the limited understanding of their impact on animal performance and meat quality. The objective of this study was to evaluate the effects of using olive pomace acid oil (OPAO) instead of its corresponding crude olive pomace oil (OPO) or crude palm oil (PO) in pig diets on lipid composition, lipid oxidation and quality of pork loin (longissimus dorsi), fresh and after commercial refrigerated storage for 8days. The experimental design consisted of feeding pigs with four diets supplemented with a 5% of PO, OPO, OPAO or a blend (B) of PO and OPAO (50:50, w/w). Fresh and refrigerated pork loin samples were assessed for fatty acid profile; tocopherol (T) and tocotrienol (T3) composition; lipid oxidative stability with the ferrous oxidation-xylenol orange method; 2-thiobarbituric acid (TBA) value; volatile compounds; colour; and sensory acceptance. Results showed that refrigeration reduced the total T+T3 levels and increased the TBA values and the volatile compound concentrations. The refrigerated storage also affected the instrumental colour parameters (L*, a* and b*) but not the overall acceptance of pork. Regarding the diet, pork from OPAO diet showed a higher unsaturated-to-saturated fatty acid ratio than pork from PO and B diets. The lowest T+T3 concentration was found in OPO and OPAO fresh pork and in OPAO refrigerated pork. The oxidative stability of fresh pork was lower for OPAO than for PO diet, but no significant effect of the diet was observed for this parameter in refrigerated pork. The TBA values and volatile compound concentrations of fresh pork were not affected by the diet. After refrigeration, OPAO pork had the highest TBA value and volatile compound concentrations. In any case, colour and consumer acceptance of pork were not affected by diet. In conclusion, in order to upcycle acid oils in pig diets, and considering results on the lipid oxidative stability of pork, it would be preferable to add the OPAO used in this study blended with PO.

Addition of fish oil microcapsules to meat products – Implications for omega-3 enrichment and salt reduction

This study aimed to evaluate the effect of fish oil microcapsules on saltiness perception of burger meats and to develop acceptable ω-3 with reduced salt. The addition of fish oil microcapsules in combination to moderate salt reduction and cooking significantly increased the quantity of ω-3 fatty acids, the acceptability, and the salty taste. These effects had a slight influence on lipid oxidation levels, or instrumental colour parameters (L*, a*, b*). The addition of fish oil microcapsules (4.5–6.5 %) in combination with salt reduction may be recommended to develop acceptable meat products labelled with nutrition claims related to sodium/salt (“reduced salt” or “low salt content”) and omega-3 (“source of omega-3 fatty acids” or “rich in omega-3 fatty acids”).

Feeding hazelnut skin to lambs delays lipid oxidation in meat

This study aimed to investigate the effect of dietary hazelnut skin (HNS), a by-product of confectionery industry, on the oxidative stability of lamb meat. Twenty-two finishing lambs were randomly assigned to 2 groups and fed ad libitum for 56 days on different concentrate-based diets: one control and one experimental, in which 150 g/kg of corn was replaced by HNS. After slaughter, the fat-soluble vitamins content and hydrophilic antioxidant capacity were assessed in fresh meat, as well as color, lipid and protein stability over 7 days of shelf-life trial. Dietary HNS increased (P < 0.001) the tocopherols content of meat and reduced (P < 0.001) lipid oxidation during 7 days of refrigerated storage. Meat from lambs fed HNS showed different (P < 0.05) instrumental color parameters. No diet effect (P > 0.05) was observed on the development of metmyoglobin, hydroperoxides, thiol groups, and carbonyl groups. Feeding HNS to lambs improves the oxidative stability of raw meat by delaying lipid oxidation thanks to the antioxidant molecules (tocopherols and phenolic compounds) contained in this by-product.

Variations of early postmortem pH in carcasses of grass-fed steers and its relationship with glycolytic potential and meat quality traits

This study aimed to investigate the multivariate relationship between the glycolytic potential, and meat quality traits from grass-fed steers carcasses with variations in early postmortem pH. From a contemporary group of steers (n=70) from the same production unit and slaughtered under similar conditions, thirty carcasses (10/group) were selected based on pH values measured at 3h (pH3h): Low (&lt; 6.2), Intermediate pH3h (6.2–6.5), and High (&gt; 6.5). Carcasses segregated by pH3h groups were different (p &lt; 0.05) in muscular glycogen (MCG), glucose (G+G6P) content, glycolytic potential (GP) and GPstrict (GP without lactate content). The interaction pH3h groups × sampling time was significant only for lactate content (LC) (p &lt; 0.05). Quality traits, except redness, did not vary (p &gt; 0.05) among pH3h groups. Color variables had a positive and moderate correlation with MGC, G+G6P, LC, and GP. Results does not allow to recommend early carcass segregation by very early pH (3h postmortem); however, important bivariate and multivariate relationships between G+G6P, lactate content and instrumental color parameters in LL muscle from grass-fed cattle were demonstrated.

High pressure processing to control Salmonella in raw pet food without compromising the freshness appearance: The impact of acidulation and frozen storage

The trend of feeding dogs and cats with raw pet food claiming health benefits poses health concerns due to the occurrence of pathogenic bacteria. High pressure processing (HPP) allows the non-thermal inactivation of microorganisms, preserving the nutritional characteristics with minimal impact on organoleptic traits of food. The present study aimed to evaluate and model the effect of HPP application (450–750 MPa for 0–7 min) on the inactivation of Salmonella, endogenous microbiota and colour of raw pet food formulated with different concentrations of lactic acid (0–7.2 g/kg) as natural antimicrobial. Additionally, the effect of a subsequent frozen storage of pressurized product was assessed.Salmonella inactivation ranged between 1 and 9 log, depending on the combination of conditions. According to the polynomial model obtained, the effect of pressure was linear, while a quadratic term was also included for holding time (depicting the occurrence of a resistant tail at ca. 4–6 min). The effect of lactic acid was dependent on the pressure level, being most relevant for treatments below 600 MPa. Frozen storage after HPP prevented the pathogen recovery and caused a further Salmonella inactivation enhanced by lactic acid in most of the treatments. Endogenous microbial groups were significantly reduced by HPP to below the detection level in several conditions. In general, little effect of HPP on the instrumental colour parameters was observed, except for a slight increase in lightness, which was hardly appreciable from visual observation.High pressure processing emerges as a relevant technology for the control of Salmonella spp. and to manage the microbiological safety of raw pet food. The mathematical model can be used as decision support tool to design safer raw pet food, while keeping the desired freshness appearance of the products.

Preparation of whey based savory beverage with enhanced bio-accessible zinc.

Zinc is an essential micronutrient for numerous catalytic, structural and regulatory functions in human body. However, its direct fortification in the food matrix poses the challenges of decreased bio-accessibility by forming insoluble sediments. Complexing zinc with polysaccharides has been reported as a possible intervention to address this issue by keeping the zinc in soluble form. Present investigation was undertaken to transform paneer whey containing complexed zinc into a sensorially acceptable beverage by varying its pH from 3.5 to 5.5, common salt concentration from 0.5 to 1.5% and spices concentration at 0.2 and 0.4%. Changes in complexed zinc concentration, apparent viscosity, instrumental color parameters and sensory attributes were determined. Complexed zinc concentration increased (p < 0.05) with increasing pH, decreasing salt and increasing spices concentration. Whey beverage having 4.5 pH, 1.0% salt and 0.4% spices concentration was most preferred by the sensory panelists. In-vitro digestion of optimized whey beverage revealed that bio-accessibility of zinc was significantly higher (p < 0.05) in complex form than free from.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13197-022-05497-y.

Quality assessment of frankfurters produced from fresh vs. frozen/thawed ground beef

In order to evaluate the effect of raw meat's freezing/thawing process on meat products produced from them, frankfurter's quality was monitored. Fresh beef meat was grounded and separated into two lots - the first lot was immediately used in the preparation of frankfurters (G1F), and the other lot was frozen and stored at -18?C for 4 weeks, when it was used in the preparation of the second group of frankfurters (G2F). Physicochemical and technological properties were investigated on fresh (CG-FM) and thawed meat (G-F/TM) samples and the frankfurters made from these samples. Frozen storage significantly affected (p&lt;0.05) moisture, TBA value, instrumental color parameters (L*a*b*), WHC, total pigment, and total heme pigment in the raw meat samples; some frankfurters characteristics, such as moisture, L*(lightness), a* (redness) and b* (yellowness) were affected (p&lt;0.05). However, the differences in the final products' process loss/cooking loss/frying loss and FRP were not significant. The sensory evaluation did not show any significance between the two groups of frankfurters It can be concluded that the frozen storage of minced beef meat for 4 weeks at -18?C and the consequential thawing process (at 4?C for 24h) does not significantly affect the overall acceptability of frankfurters prepared from them. However, effects on the marked changes in instrumental color are apparent.

Effect of Natural Sorbents in the Diet of Fattening Pigs on Meat Quality and Suitability for Processing.

Simple SummaryAnimal production generates emissions of gaseous pollutants to the environment. Natural sorbents are used to reduce emissions increase feed safety and reduce the impact of farms on the environment. Therefore, the aim of the study was to assess the effect of three natural sorbents added to the diet of pigs on the composition and physicochemical properties of two skeletal muscles (Longissimus lumborum and semimembranosus) of crossbred pigs. The experiment was carried out on a farm in two production cycles. The animals received feed supplemented with three different natural sorbents. The results indicate that the sorbents used in the diet of pigs have no negative effect on the physicochemical properties of meat or its use as case-ready meat or material for processing.The effect of three natural sorbents added to the diet of pigs on the composition and physicochemical properties of two skeletal muscles—the musculus Longissimus lumborum (MLL) and musculus semimembranosus (MSM) of crossbred pigs were evaluated. The experiment was carried out on a farm in two production cycles. The addition of biochar (trial 1) significantly influenced instrumental color parameters, shear force and energy, and the oxidative stability of the skeletal muscles, while the proximate composition, pH, texture, and water-holding capacity (WHC) parameters did not differ significantly between groups in either of the two muscles. Similarly, no statistical differences were noted in the proximate chemical composition, texture parameters, or WHC of the meat in trial 2. The addition of both sorbents was associated with a significantly (p ≤ 0.01) lower content of haem pigments in the MLL and MSM, which was accompanied by a significantly (p ≤ 0.05) higher lightness (L*). Moreover, the MLL muscle of the pigs had higher oxidative stability, as well as lower drip loss (DL). In turn, the MSM of pigs had a significantly lower pH compared to the control group, however, the ultimate pH (48 h) in all groups was within the acceptable range (5.50–5.80). Summing up, the sorbents used are a safe ingredient in the diet of pigs, however, there is a need to continue and strengthen this line of research, including the relationships linking the future production goals of pig farming and processing potential in the meat industry with current climate policy.

Domestic Use Simulation and Secondary Shelf Life Assessment of Industrial Pesto alla genovese.

The secondary shelf life (SSL) is defined as the time after package opening during which the food product retains a required level of quality. The SSL, indicated in labels as “best if used within x days after opening”, could lead to domestic food waste if not correctly evaluated. In this context, the SSL of two brands of industrial shelf-stable pesto products (with an indicated SSL of 5 days) was studied through a domestic use simulation performed in five households under two scenarios simulating real opening and storage conditions. The quality of pesto after opening was assessed through microbiological and sensory analyses, determination of instrumental colour parameters, pH and volatiles profiling. For both pesto sauces tested, a SSL ≥ 20 days was proven. Irrespective of the intensity of use (scenarios 1 and 2), the pesto was microbiologically stable: the maximum count for total aerobic mesophilic bacteria (TMB) observed during 20 days of storage was 9.64 ± 1.7 × 102 CFU/g, starting from a commercially stable product. Colour parameters L* and ΔE did not change significantly during storage (p > 0.05), while the a* and BI values significantly changed (p < 0.05) during the first 5 days, and then stabilized during the rest of the household storage. Nevertheless, the slight colour modifications were not perceived by the sensory panel. Moreover, sensory assessors were not able to discern pesto samples stored for up to 20 days after first opening, from a just-opened reference sample, proving that the sensory appreciation of pesto was not influenced by the time after opening. The results of this study suggest the possibility to significantly extend or even omit the SSL indications for industrial pesto sauces. The objective assessment of SSL could have impressive practical outcomes both for the industry and the end user. The elongation of the SSL on the food label might increase food sustainability, thanks to the potential reduction of food wastes, thus giving added value to the commercial products. In addition, the end user could benefit the increase of the useful period for the food consumption after first opening, with significant domestic food waste reduction, reduced household stock turnover and consequent cost savings.

Custard apple puree, fructooligosaccharide and soy protein hydrolysate as alternative ingredients in low carb pound cake.

The online version contains supplementary material available at 10.1007/s13197-021-05155-9.

Evaluation of instrumental and sensory measurements using multivariate analysis in probiotic yogurt enriched with almond milk.

Highlights Consumers demand the purchase of fortified dairy products.Instrumental (color, texture) and sensorial attributes are critical tests for novel food.Almond milk has high nutritional value with unique textural and sensorial properties.Almond milk is an innovative and attractive additive in probiotic yogurt. In this study, the effect of almond milk addition on color, texture and sensory attributes of probiotic yogurt was investigated. The data generated in combination with instrumental (color and texture parameters) and sensory measurements was analysed statistically to describe a product’s attributes scientifically. Statistical analysis illustrated that almond milk rate and storage time had a significant (P < 0.05) effect on the color and textural parameters of yogurt. Compared with the sensorial parameters, generally there were statistically significant differences among samples, whereas insignificant effect was determined among storage days. The results of descriptive statistics (Principle Component and Hierarchical Cluster Analysis) indicated that the relationships among the analysed attributes were determined. In addition, statistical data has demonstrated that almond milk may be used as a novel and functional ingredient in both industrial and research areas for development, innovation, quality, and safety of dairy products.

Gluten-free pasta elaborated with taro flour (Colocasia esculenta): a study of the employ of egg white and transglutaminase on the technological properties

Taro (Colocasia esculenta), like any tuber, lacks the proteins that form the gluten network, making it a possible source of carbohydrates in the production of gluten-free products. This study aimed to enable the production of gluten-free pasta elaborated with taro flour. To help with the pasta structure, egg white was used as a protein source, and the transglutaminase enzyme was used as a processing aid. Pasta was produced with varying the contents of egg white powder (5 to 50% replacement in flour) and transglutaminase (0.005 to 0.05% flour base) according to a complete 2² factorial design containing 7 assays. The pasta was evaluated for pH, instrumental color parameters, cooking properties, and texture. The results were analyzed using Response Surface Methodology. Egg white contributed to increasing the chroma and hue angle, while transglutaminase only increased the chroma. Both egg white and transglutaminase showed a positive interaction effect for cooking time and increased weight of cooked pasta, and a negative interaction effect on firmness. However, these raw materials had no significant effect on the volume increase of the cooked pasta and cooking loss. The lowest contents of egg white and transglutaminase enzyme used in this study have already sufficient to structure the gluten-free pasta elaborated with taro flour, which provides adequate technological characteristics to it.

Changes of sensory atributes of chilled vacuum-packaged cold-smoked common carp (Cyprinus carpio) and cold-smoked bighead carp (Hypophthalmichthys nobilis) fillets

The aim of this research was to monitor changes of selected sensory properties and instrumental colour parameters (L*, a*, b*) of vacuum-packaged cold-smoked common carp (Cyprinus carpio) and cold-smoked bighead carp (Hypophthalmichthys nobilis) fillets during storage at 3 ? 0.5?C and to determine the shelf life of the products. Sensory tests and instrumental color determination were performed on days 1, 7, 10, 12, 14, 15, and 16 of storage. All estimated sensory characteristics of common carp samples received significantly lower (P &lt; 0.05) score on day 15. ?Musty? odour of common carp samples detected on day 16 caused that odour score was below the acceptability limit of 2. On the last day of experiment, reduced intensity of pink cream colouring of carp muscle was observed together with softened texture and surface slime. A decrease of scores of the sensory attributes of cold-smoked bighead carp fillets was observed throughout the storage period. However, all estimated sensory characteristics were within the acceptability level. Significant increase (p &lt; 0.05) of L* value was noted in both group of samples, while redness (a*) and yellowness (b*) remaid quit stable during the storage. Based on the sensory results, it was concluded that vacuumpackaged cold-smoked common carp samples remained acceptable for up to 15 days of storage, whereas vacuum packaged cold-smoked bighead carp samples remained unchanged until the end of the experiment.

Evaluation of the combined effect of temperature and potassium sorbate on physicochemical and microbial quality of modified atmosphere packaged sliced Mozzarella cheese

This study aimed to evaluate the influence of storage (5°C) and abuse (15°C) temperatures and the addition of potassium sorbate (PS) on different quality attributes of modified atmosphere packaged (MAP) sliced Mozzarella cheese. It was observed that the temperature affected more significantly the cheese properties than the addition of PS in sliced MAP cheese. After 15 and 45 days of storage, the pH has decreased and the acidity has increased at 15°C. The instrumental color parameters were practically temperature and PS independent. Empirical equations that estimate the kinetics of change of the quality attributes in terms of the temperature, storage time, and PS were derived. Regarding the microbiological quality, the psychrotrophic bacterial population continued to grow during the storage independently on the treatment. Depending on the treatment adopted, LAB, yeasts and molds, and Escherichia coli population decreased during the period of 75 days of storage. Practical applications The results obtained in the current study provide a quantitative evaluation of the influence of these independent variables on cheese quality. Empirical equations that estimate the rate of changes in the physicochemical and microbiological parameters were derived and can be used to evaluate the shelf life of sliced MAP Mozzarella cheese subjected to different storage conditions. Such information can help consumers and industry to optimize storage parameters of the product.

Quality of grape tomatoes in differents cultivation systems

Tomato is a fruit rich in bioactive compounds like lycopene, vitamin C and phenolic compounds. However, cultivation conditions can influence the concentration of these substances. In this study, the objective was to analyze quality characteristics of tomato fruits in different cultivation systems. The following characteristics were evaluated: pH, soluble solids content, total acidity, relationship between soluble solids content and total acidity, instrumental color parameters (L *, a *, b *, chroma and hue), texture, bioactive compounds (total carotenoids, lycopene, total phenolic compounds and vitamin C) and antioxidant activity of grape tomato fruits grown in a greenhouse in different systems (soil x substrate). A completely randomized design was used, with two treatments and four replications. The analysis were performed by official methods and in triplicate. The pH, soluble solids, texture, color, lycopene, vitamins C and antioxidant activity were not affected by the cultivation system used. However, grape-type tomatoes grown in substrate showed higher levels of carotenoids (36.31 µg.100 g-1 fresh matter), phenolic compounds (68.37 mg GAE.100 g-1 fresh matter) and ratio between total soluble solids and total acidity (17.90), and lower total acidity (0.58% citric acid 100 g-1), which represents a nutritional, sensorial and functional advantage for the consumer.