Sensory Rejection Research Articles

Enhancing saltiness perception in bone broth: the additive effect of oil and optimization of sodium-reduction formula for consumer acceptability.

Excessive NaCl intake in liquid and semi-solid food (e.g. soup, hot pot base, sauce) poses a high risk to human health, and reducing NaCl intake is a major concern for global health. Using the generalized Labeled Magnitude Scale (gLMS) method, the study verified the possibility of sodium reduction through oil addition. The compromised acceptance threshold (CAT) and hedonic rejection threshold (HRT) were determined. The gLMS results showed that the saltiness intensity of samples containing 0.36% NaCl and 2.29% sunflower seed oil was significantly higher than that of samples containing only 0.36% NaCl (P < 0.05). CAT and HRT results indicated that by adding 3.59% sunflower oil, the NaCl content could be reduced to a minimum of 0.14% without causing sensory rejection in bone broth samples. The quantitative descriptive analysis method was used to determine the effects of NaCl and oil concentrations on the sensory attributes of bone broth samples. Furthermore, it was used to analyze the consumer acceptability drivers in combination with the hedonic scale to optimize the formulation of reduced-salt bone broth products. Notably, sample E (0.36% NaCl, 2.29% fat) not only had a significant salt reduction effect with a 20% decrease in NaCl, but also had improved overall acceptability. This study provides theoretical guidance for designing salt-reduction cuisine within the catering and food industries, including bone broth and hot pot bases. © 2024 Society of Chemical Industry.

Bebida deportiva isotónica a base de jugo de piña: Estabilidad durante su almacenamiento acelerado

It was evaluated the behavior, during accelerated storage, of the quality indicators of an isotonic sport drink made from the mixture of pineapple juice, distilled water, sucrose and NaCl. The drink was packed in amber glass bottles was pasteurized at 80 °C for 5 min in a water bath. The drink was stored at 45, 50 and 55 °C with the aim of achieving accelerated deterioration. The drink presented a total sugar content of 7.6%, osmolality of 328 mOsm/kg and sensory acceptance corresponding to the category -I like it slightly-. At the end of storage at each temperature, there was a decrease in brightness and an increase in the values of a* and b*, related to the increase (p ≤ 0.05) of the browning index (IP) and the moment of sensory rejection, due to a notable loss of pineapple color. The behaviors of the IP at each temperature were adjusted to polynomial models of order five with high coefficients of determination (&gt; 0.98). This study provides useful information for the optimization of beverage production, quality control and spoilage prediction, which could contribute to the development of new products and satisfy consumer needs.

Incorporation of jaggery in beetroot jam enhances its antioxidant properties with acceptable sensory and physicochemical profile

With the growing consumer interest in incorporating healthier foods in diet, the market for functional foods is increasing. The present study focused on developing beetroot jam (BJ) using jaggery (non-centrifugal sugar) as a sweetener. Formulation of BJ was carried out by partial replacement of sugar with jaggery and evaluated for sensory attributes (odor, color, spreadability, taste, acid attribute and overall acceptance) using compromised acceptance threshold (CAT) and the hedonic rejection threshold (HRT). The incorporation of jaggery in BJ shifted the acceptances of tatse (CATt = 82.56%), color (CATc = 78.82%), odor (CATo = 73.16%), acid attribute (CATac = 65.01%), overall acceptance (CAToc = 65.61%), and spreadabality (CATs=50.94%). This depreciation, however, did not result in sensory rejection of the jam odor, color, and taste. On the other hand, a sensory rejection started to occur for spreadability, acid attribute, and overall acceptance at jaggery concentrations of 66.92%, 88.1%, and 77.49%, respectively. Physicochemical characterization of BJ for parameters such as color, texture, and rheological properties was carried out. Thermal behaviour of BJ was studied using differential scanning calorimetry (DSC), whereas chemical characterization was performed using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Assessment of nutraceutical and nutritional properties of BJ revealed that an increase in jaggery proportion resulted in an increase in total phenolic content (TPC) and total flavonoid content (TFC), where BJ100 showed the highest TPC and TFC of 2.58 mg GAE/g and 1.08 mg QE/g, respectively. The increase in the polyphenols in BJ correlated positively with the antioxidant activities evaluated through DPPH, FRAP, and ABTS assays. Lastly, the proximate analysis of BJ was carried out for protein, fat, carbohydrates, sugar, and fibre content.

Quality changes, potential spoilage organisms, and shelf-life prediction of brackish river prawn (Macrobrachium macrobrachion) at different storage temperatures

The brackish river prawn (Macrobrachium macrobrachion) is a species of commercial importance in West Africa. However, like other fishery products, it is prone to deterioration due mainly to microbial activities. The present study aimed at evaluating the spoilage characteristics of M. macrobrachion and predicting the growth of the main spoilage bacteria as well as the shelf-life of the product as a function of storage temperature. Freshly caught brackish river prawn samples from Lake Aheme were aerobically stored at 0, 7, 15, and 28 °C and, at pre-determined times during storage, they were taken for microbiological, chemical, and sensory analysis. At sensory rejection times, the spoilage potential of 185 isolates from specific groups of organisms enumerated was assessed in prawn of which the endogenous microbiota was heat inactivated. Isolates capable of producing strong off-odor were identified using 16S rRNA sequencing. Models predicting the maximum growth rate of Pseudomonas spp. and H2S-producing bacteria in the brackish river prawn as well as the shelf-life of the product were developed. These models were validated using an independent experiment during which prawn was stored at 0, 4, 10, and 25 °C. Results showed that Pseudomonas spp. at 0 °C, Pseudomonas spp. and H2S-producing bacteria at 7 °C, and H2S-producing bacteria at 15 °C and 28 °C were the dominant groups of microorganisms during storage. As expected, total volatile basic nitrogen, trimethylamine, and pH with initial values of 21.2 ± 3.0 mg-N/100 g, 4.1 ± 0.8 mg-N/100 g, and 7.46 ± 0.15 increased during storage reaching approximately 35 mg-N/100 g, 10 mg/ 100 g and 8, respectively at sensory rejection times which were 7 h at 28 °C, 1.2 d at 15 °C, 4.6 d at 7 °C, and 11.7 d at 0 °C. The main spoilage organisms were Citrobacter braakii at 28 °C, Citrobacter braakii, Pseudomonas kurunegalensis, and Shewanella bicestrii at 15 °C, Shewanella putrefaciens, Shewanella baltica, and Pseudomonas bubulae at 7 °C, and Pseudomonas versuta at 0 °C. The validation of the developed models showed an adequate agreement between the predicted and observed values. This study highlights the specific spoilage characteristics of the brackish river prawn and reveals that Gram-negative rod bacteria are the main spoilage organisms even at high storage temperatures, contrary to many earlier reports on the spoilage of tropical fishery products.

Effect of alginate-gallic acid coating on freshness and flavor properties of Mackerel (Scomberomorus commerson) fillets under refrigerated storage

This study investigates the effect of sodium alginate-gallic acid (ALG-GAL) coating on mackerel's flavor compounds and quality properties during cold storage at 4 °C for 12 days. To this end, freshness quality indicators, including biogenic amines (BAs), volatile organic compounds (VOCs), ATP-related compounds, K value, total viable counts (TVC), thiobarbituric acid (TBA), and sensory assessment, were measured. During storage, eight BAs, i.e., histamine (HIS), tyramine (TYR), putrescine (PUT), cadaverine (CAD), 2-phenylethylamine (2-PHE), agimation, spermine (SPM), and spermidine (SPD) were identified in control and treated samples. The biogenic amine index (BAI) for control samples was 56.25 at the time of sensory rejection (day 6). BAI for samples coated with ALG-GAL did not exceed 20 mg/100 g at the time of sensory rejection (day 12). The fillets treated with the ALG alone or incorporated with GAL possessed a different trend in the retardation of VOCs, including aldehydes, ketones, alcohols, and hydrocarbons. Seven key flavors VOCs, including 3-methylbutanal, phenylacetaldehyde, E-2-hexanal, 1-hexanol, 1-octen-3-ol, 2,3 pentanedione, and hydroxyl-2-butanone, were identified in control and coated samples. Samples coated with ALG and GAL were of significantly higher quality (p < 0.05) throughout storage, which could result in lower Inosine (HxR) concentrations and K values. The results of TVC showed that use ALG-GAL had lower bacterial counts compared to control (p < 0.05). The ALG-GAL-coated samples retarded the increase in the contents of TBA during storage. In addition, significant differences in sensory scores between ALG and ALG-GAL were observed (p < 0.05). In this study, aldehydes and hypoxanthine (Hx) were the main compounds in the formation of off-flavor. These results revealed that ALG coating combined with GAL improved the quality of refrigerated mackerel fillets by decreasing off-flavor compounds and TVC population.

Change in fat skatole and indole content in lambs switched from a concentrate-based diet indoors to alfalfa grazing for various durations before slaughter

Meat from lambs fattened on alfalfa is at risk of excessive pastoral flavours due to high levels of in-fat volatile indolic compounds (especially, skatole). Skatole has also been identified as a potential marker of interest for authenticating pasture-fed lamb meat. Here, we investigated the change in skatole and indole concentrations in kidney fat from lambs switched from an indoor-fed concentrate based diet to outdoor alfalfa grazing for various durations (0, 21, 42, 63 days) before slaughter. The study used a total of 219 lambs over 3 consecutive years. Kidney-fat skatole and indole concentrations increased from as early as 21 days on alfalfa, and then reached a plateau. Similarly, the proportion of lambs that had a kidney fat-skatole concentration above 0.15 μg/g liquid fat, a value that has been established as a sensory rejection threshold for pork, increased significantly from as early as 21 days on alfalfa and then reached a plateau. This value was reached or exceeded in a significant proportion of lambs fattened on alfalfa pastures (45.1%). However, skatole was not detected in kidney fat from 20 out of 164 alfalfa-fattened lambs (i.e., 12.2%) but was detected in 15 out of 55 concentrate-fed lambs (i.e., 27.3%). We thus conclude that while skatole content in kidney fat can inform on dietary changes made shortly before slaughter, it does not have the discrimination power needed to reliably authenticate pasture-fed lamb meat, let alone duration of finishing on pasture.

Quantitative microbiological spoilage risk assessment (QMSRA) of fresh poultry fillets during storage at retail

A quantitative microbiological spoilage risk assessment model (QMSRA) of aerobically stored fresh poultry fillets was developed based on pseudomonads growth and metabolic activity. Simultaneous microbiological and sensory analyses were performed in poultry fillets to evaluate the relation between pseudomonads concentration and sensory rejection due to spoilage. The analysis showed no organoleptic rejection at pseudomonads concentrations less than 6.08 log CFU/cm2. For higher concentrations, a “spoilage-response” relationship was developed using a beta-Poisson model. The above relationship was combined with a stochastic modeling approach for pseudomonads growth by taking into account both variability and uncertainty of factors affecting spoilage. To enhance the reliability of the developed QMSRA model, uncertainty was quantified and separated from variability using a second order Monte Carlo simulation. For a batch of 10,000 units, the QMSRA model predicted a median number of 11, 80, 295, 733 and 1,389 spoiled units for retail storage times of 6,7, 8, 9 and 10 days, respectively, while no spoiled units were predicted for storage time of up to 5 days at retail. Scenario analysis showed that a reduction of 1 log in the pseudomonads concentration at the time of packaging or 1 °C in retail storage temperature results in up to 90% reduction of the spoiled units while the combination of the above interventions can reduce the risk of spoilage by up to 99%, depending on the storage time. The poultry industry can utilize the QMSRA model as a transparent scientific basis to support food quality management decisions in determining appropriate expiration dates which maximize the utilization of the product’s “true” shelf life while minimize the risk of spoilage to an acceptable level. Furthermore, the scenario analysis can provide the necessary components for an effective cost-benefit analysis, enabling the identification and comparison of appropriate strategies for extending the shelf life of fresh poultry products.

A Quality Index Method-based evaluation of sensory quality of red mullet (Mullus barbatus) and its shelf-life determination.

Every day the consumer must choose a food product rather than others based on its quality; for fishery products the main quality parameter is freshness. Implementation of the Quality Index Method (QIM) in the fish industry provides information on fish quality; therefore, it is important for effective quality and process management in the production of high-quality fish products. The present study aims to validate the shelflife study of fresh red mullet (Mullus barbatus) stored in ice previously presented by Özyurt in 2009 through Torry scheme in cooked filet and microbiological evaluation. Next, this revised scheme was applied to determine the shelf-life. It included seven descriptors and varies from 0 to 15 points. The use of a modified QIM scheme showed a good correlation between the quality index and days of storage time, with a R2 value of 0.9698. In fact, all the subjects examined reached the end of their commercial life, or the day of sensory rejection, in 9-10 days with a Quality Index of 13.83.

Influence of soaking and solvent extraction for deodorization of texturized pea protein isolate on the formulation and properties of hybrid meat patties.

Hybrid batters constitute the base for the processing of cooked and dry meat analogues. The use of texturized plant proteins in their formulation is a key strategy to reduce the consumption of animal proteins, although off-flavors present in these plant proteins often cause sensory rejection. The aim was to study the effect of a deodorization process of pea protein, for their use in hybrid meat batters at different percentages of substitution. Hybrid patties with higher percentages of pea protein showed higher values of yellowness, pH, and water activity, whereas hardness was reduced. Soaking treatment with ethanol for deodorization of the texturized pea protein increased humidity and pH in all patties but reduced the textural properties (hardness, springiness, cohesiveness, and chewiness). The addition of oat flour improved the patty texture at higher percentages of pea protein, but in soaked deodorized patty formulations it affected volatile retention. Volatile compounds related to off-flavors (aldehydes, alcohols, acid compounds, ketones, and pyrazines) appeared significantly increased as the pea percentage increased, although these were efficiently removed by the soaking deodorizing process applied. Soaking of the texturized pea protein with ethanol is an effective strategy to reduce off-flavors in hybrid meat patties. However, it produces changes in the textural characteristics by the solubilization of the proteins of the texturized pea, reducing the availability to form a network and affecting volatile retention. The formulation of hybrid batter should be controlled in all sensory aspects for the processing of cooked and dry cured meat product analogues. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Quality index method developed for raw anglerfish (Lophius piscatorius) stored in ice.

The quality index method (QIM) is a widely accepted solution to establish the state of fish freshness quickly and effectively. The present study aims to determine increasingly reliable freshness parameters for fresh and whole Lophius piscatorius stored in ice. Sensory and microbiological analyses were performed on 148 anglerfishes. Sensory evaluations were performed based on the QIM, updating a previously proposed quality index (QI) scheme. Total viable count and specific spoilage organisms were determined through microbiological analyses of the tail musculature, evaluating their correlations with the QI scores over time. The updated QI scheme included 3 characters, namely appearance, eye, and fin, for a total of 18 demerits points. A positive linear correlation between QI score and storage time was observed such that the sensory rejection time (8th day) can be predicted within ± 1day with the developed scheme. At the sensory rejection point, loads of the spoilage microbial flora were not high enough to be relatable to the appreciated alterations probably due to the anglerfish morphology in which the tail musculature is isolated from the gills and viscera, the main sources of bacterial contamination. The proposed scheme offers a ready-to-use freshness assessment of the anglerfish although further validations are needed.

Determination of hedonic thresholds by varying three stimuli

The Hedonic Threshold Methodology (HTM), through the determination of compromised acceptance threshold (CAT) and hedonic rejection threshold (HRT), has several applications by the food industry. In order to further increase the field of application of HTM, the objective was to use a mixture design in the Hedonic Threshold Methodology, to enable the determination of hedonic thresholds (CAT and HRT) by varying the intensity of three stimuli simultaneously. It was investigated how much it is possible to replace the NaCl content (1.8% flour weight basis) with two other ingredients (KCL/yeast extract or KCL/enzyme preparation), without compromising the acceptance (CAT) and without resulting in sensory rejection (HRT) of crackers. Reduction in the acceptance started to occur by reducing the NaCl content by around 64% (from 1.81% to 0.651%), with the addition of 1.149% KCl. Two combinations of KCl and yeast extract (1.783% and 0.017%, or 0.693% and 1.107%, respectively) allowed producing a cracker with no NaCl without sensory rejection. The reduction in acceptance also started to occur by reducing the NaCl content by around 40% (from 1.81% to 1.086%), with adding of 0.358% KCl and 0.356% enzyme preparation. A sensory rejection begins to occur by reducing the NaCl content by around 99% (1.81–0.012%), with the addition of 1.215% KCl and 0.573% enzyme preparation (transglutaminase). The use of the mixture design in HTM allowed the unprecedented determination of hedonic thresholds varying three stimuli. This expands the possibilities for applications of sensory thresholds.

Preservation status and microbial communities of vacuum-packed hot smoked rainbow trout fillets

Vacuum-packed hot smoked rainbow trout fillets from two different smokehouses of Greece were stored at 2 and 7.9 °C. Microbiological, sensory, and physicochemical changes were monitored. Microbial communities grown on MRS of three different pHs (5.4, 6.4 and 7.4) were also classified and identified using Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). Shelf-life was found to differ between products from the two smokehouses (A: 104 and 45 days, B: 100 and 45 days, at 2 and 7.9 °C, respectively). At the time point that sensory rejection was recorded, counts on MRS were found at higher population levels than the other microorganisms tested, almost in all cases. Out of the 567 colonies isolated from MRS of three different pHs, 71 classified as Enterococcus spp., 383 as Candida spp. and 113 as Lactobacillus spp.. Candida zeylanoides dominated exclusively in fillets from the smokehouse A during storage at 2 °C, while Lactobacillus sakei dominated clearly against C. zeylanoides at 7.9 °C, in all pH values. For the smokehouse B, C. zeylanoides or Enterococcus faecalis found to dominate initially in MRS of three pHs, C. zeylanoides, and/or Candida famata in the middle and/or the time point that sensory rejection was recorded at 2 °C, while Lactobacillus curvatus or E. faecalis at 7.9 °C. This study reveals the predominant cultivable spoilage microbiota of vacuum-packed hot smoked rainbow trout, and provides valuable information to the researcher and producers towards the production of more stable products with improved shelf-life.

How much can sodium chloride be substituted for potassium chloride without affecting the sensory acceptance of cracker-type biscuits?

Excessive sodium consumption is a worldwide public health concern. The substitution of sodium chloride (NaCl) for potassium chloride (KCl) has been adopted to reduce the sodium concentration in processed foods. The challenge is to make this substitution without affecting the sensory acceptance of foods. In this context, the objective was to determine from which concentrations the replacement of NaCl by KCl results in reduced acceptance (compromised acceptance threshold - CAT) and begins the sensory rejection (hedonic rejection threshold - HRT) of cracker-type biscuits. Using the hedonic thresholds methodology (HTM) by varying a stimulus, CAT and HRT were determined for the concentration of NaCl in crackers and, by varying two stimuli, CAT and HRT, for replacing NaCl with KCl in crackers were determined. Without the addition of KCl, the reduction in acceptance started to occur by reducing the NaCl content by around 60% (from 1.81% to 0.73%); and sensory rejection began to appear by reducing the NaCl content by approximately 93% (1.81% to 0.13%). Reduction in the acceptance started to occur by lowering the NaCl content by around 78% (from 1.81% to 0.397%), with the addition of 0.896% KCl. In addition, by adding KCl, it was possible to reduce 100% NaCl without sensory rejection of the crackers. With these results, cracker industries can reduce the sodium content of their products, contributing to the reduction of population salt intake.

Combined Effect of Impregnation with an Origanum vulgare Infusion and Osmotic Treatment on the Shelf Life and Quality of Chilled Chicken Fillets.

The scope of this work is the study of a combined process including a dipping step into an oregano (Origanum vulgare ssp. hirtum) infusion (OV) followed by osmotic treatment of chicken fillets at 15 °C. Chicken fillets were immersed in an osmotic solution consisting of 40% glycerol and 5% NaCl with (OV/OD) and without (OD) prior antioxidant enrichment in a hypotonic oregano solution. A comparative shelf life study of all the samples (untreated, OD and OV/OD treated) was then conducted at 4 °C in order to assess the impact of this process on the quality and shelf life of chilled chicken fillets. Microbial growth, lipid oxidation and color/texture changes were measured throughout the chilled storage period. Rates of microbial growth of pretreated fillets were significantly reduced, mainly as a result of water activity decrease (OD step). Rancidity development closely related to off odors and sensory rejection was greatly inhibited in treated fillets owing to both inhibitory factors (OD and OV), with water-soluble phenols (OV step) exhibiting the main antioxidant effect. Shelf life of treated chicken fillets exhibited a more than three-fold increase as compared to the untreated samples based on both chemical and microbial spoilage indices, maintaining a positive and pleasant sensory profile throughout the storage period examined.

Canine vegan biscuits produced with inulin and blackberry flour

Pet food accounts for more than 60% of the total sales in the pet market, with emphasis on products with the addition of functional ingredients and health claims. The objective of the present study was to manufacture vegan canine biscuits, as snacks, containing the following functional ingredients: inulin, blackberry flour (BBF), and hydrolyzed soy protein (HSP). Four formulations were made, as follows: CB1, a control formulation, without the addition of inulin, BBF, and HSP. For the other formulations, the amount of BBF and HSP was set at 50 and 35 g/kg, respectively, and the inulin contents were 30, 60, and 90 g/kg, for the formulations CB2, CB3, and CB4, respectively. All biscuits were evaluated for their technological properties. The increase in inulin significantly reduced the hardness of the biscuits from 30 N (CB1) to 20 N (CB3 and CB4). The biscuits with blackberry exhibited a pink color, which shows that this natural ingredient can be used as a food coloring ingredient, thus avoiding the use of synthetic additives. CB3 and CB4 had the same acceptance as CB1, indicating no sensory rejection of the ingredients by the dogs. The BBF increased (p-value&lt;0.05) the total phenolics content and the antioxidant capacity, and inulin increased (p-value&lt;0.05) the prebiotic activity in relation to the control. The study demonstrated that color-conferring ingredients with bioactive compounds can be used in canine biscuits formulations, with no changes in the sensory acceptance, which can be an effective alternative to include the functional ingredients while maintaining the health appeal and clean label of the products.

Low‐sugar strawberry yogurt: Hedonic thresholds and expectations

AbstractSugar reductions in processed foods can impact a product's sensory aspects and lead to financial losses for the companies that produce them. The aim of the present study was to determine sucrose levels in strawberry yogurt production that would not compromise acceptance (compromised acceptance threshold [CAT]) or result in sensory rejection (hedonic rejection threshold [HRT]). Second, the consumers' expectations were assessed by comparing sensory acceptability of the samples in blind and informed tests to verify the impact of reduced sugar content information on consumer perceptions. The ideal sweetness level of the sampled products was also evaluated. Finally, reduced sugar samples were evaluated with regards to meeting the new national requirements for reduced sucrose yogurts. Samples with a 9.13% sucrose concentration CAT and a 6.36% HRT were obtained when using the hedonic threshold methodology (HTM), from a control sample containing 10.64% sucrose. Over 14% of the sucrose in yogurt can be reduced without altering sensory acceptance, but a 40% or greater reduction in sucrose content may lead to sensory rejection of strawberry yogurt. The present study demonstrated that reductions which meet the required Brazilian standards can be made without affecting sensory acceptance.Practical ApplicationsThis was the first study to use the HTM to study sucrose reduction in dairy products. The results presented herein could have an important impact on industry, public policy makers, and consumers and may help dairy manufacturers meet established sugar reduction goals without affecting sensory acceptance. The effects are an important contribution to food science even when there are no sugar reduction requirements in play. Companies that have tested the impact of sugar reduction and studied how much sugar can be appropriately removed will be ahead of their competitors when these dietary requirements are implemented.

Research Article: Determination of freshness quality changes using selective methods: A comparative study for eclipse parrotfish (Scarus russelii) and spangled emperor (Lethrinus nebulosus)

The present study was carried out to determine freshness quality and remaining storage time of eclipse parrotfish and spangled emperor stored in ice on days 0, 2, 3, 5, 7, 9, 12, 15, 19 and 21 using selective methods. A score of 11-12 coincided with the level at which the fish were considered unacceptable by a sensory panel of six experienced assessors. The demerit score of eclipse parrotfish and spangled emperor increased linearly (R2=0.9563 and 0.9624, respectively) with storage time. The limit for acceptability of eclipse parrotfish and spangled emperor stored in ice was 9 and 19 days respectively. Total volatile base nitrogen value (45.87±1.10 mg/100g) for parrotfish stored in refrigerator exceeded limit of acceptability at the time of sensory rejection (9th day) while the value (5.93±0.28 mg/100 g) for spangled emperor was remained below the limit of acceptability after 9 days and increased to 54.96±1.80 mg/100g at the 19th day. The pH for both fishes showed significant (p <0.05) increases during the storage. Total viable count in spangled emperor analyzed were found to be below the acceptability limits (6 log10 cfu/g) by 15 days while maximum level of acceptability of eclipse parrotfish was until 7 days. Shelf-life of both fishes was different. Sensory score, value of TVB-N, pH and TVC provide evidence that the limit for acceptability was 7 days for eclipse parrotfish and 15 days for spangled emperor stored at 0 - 20C.

Fortification Effects in Preparation of Fresh Cheese (&amp;lt;i&amp;gt;Quesoblanco, Gybna beyda &amp; Halloumi&amp;lt;/i&amp;gt;) of Zebu Cow Milk Using Citric Acid Solution, Gambella, Godere Woreda, Ethiopia

Food Technology is on sustainable, priority area with competitive and efficient agri-food production and processing, encompassing and manufacture of safe, value added and innovative foods from milk. The research results revealed that fresh cheese fortification and DMs effects on storage durability, trace-nutrients, anti-nutrients & perception of processed & preserved fresh cheese. The experiment was conducted 3×3×2 in design of treatments expressed as 3 varieties of preserved fresh cheeses like G, H & Q, 3 preservatives (solanum, lemon juice & salt) and 2DMs (sun & oven drying) laid out in CRD. Preserved samples were checked for their safety followed by sensory evaluation & proximate analyses in each month. A total of 4.42 log10 cfu/g AeB was observed in fresh samples with absence of fungi in all varieties of preserved fresh cheeses. MC in freshly preserved was within 23-36% where as high load of 4.0-4.42 log10cfu/g AeB with (P>0.05) significant difference was observed in samples. Initial load of<1.31 log10cfu/g moulds were recorded. After three months of storage, max load of AeB & moulds were 4.83-6.65 and 0-6log10cfu/g, respectively. All parameters under the proximate analyses were vary due to absorption of moisture at ambient condition during the storage time. OA of treated samples reached min & max values of 4.83 and 5.33 after the storage of 3 months respectively. Overall load of 6.65 log10cfu/g AeB in almost all samples was detected and reasonable those samples were not allowed for panelists for taste after the three months storage. This was due to the ISO and EU sensory guidelines showed the point of sensory rejection in which the number of microbial load should be below the 107-108 log10cfu/g. In general, as the storage time of preserved cheese products increased, there were an increased of microbial population and reduction in acceptability of the products through the sample storage of three months. Fresh zebu cow milk was preserved in to new developed products (G, H and Q), lemon fruit juice and salt were used for the indicated preserved products. Anti-nutrient contents such as Hg and aflatoxin were negligible based on international standard requirements. The chemical composition of preserved fresh cheese products contents ranged in MC (23-37%), protein (19.67-40.33%), fat (13.67-32.33), ash (1-8.33%), CHO (10.67-86.67), energy (340.33-454.33kcal), Ca (720-1208g/100mg), Fe (25-41.67g/100g), Zn (4-11.67g/100g) and null contents of Hg were approved based on data analyzed in this research. Eventually, food innovation is a key of any society from local goods is made as an inference of this research work.

The hedonic thresholds methodology varying two stimuli: Extending the range of sensory threshold applications

In several situations it is desired to simultaneously alter the intensities of two food stimuli without affecting acceptance or causing sensory rejection. However, at present it is only possible to determine sensory thresholds by varying just one stimulus at a time. The objective of this study was to propose a new methodology, the Hedonic Thresholds Methodology Varying Two Stimuli (HTM2s), which allows for determining the compromised acceptance threshold and the hedonic rejection threshold by simultaneously varying the intensities of two stimuli in a food. For this purpose, the central composite rotatable design was used, with response surface graphs, obtaining the equations that allow for calculating the different intensity combinations of the two stimuli that result in the beginning of compromised acceptance (CAT) and the beginning of sensory rejection (HRT) of the product. It was found that by adding 0.96% garlic powder only to reduce the hamburger sodium concentration from 0.827% to 0.2504%, sensory acceptance of the product began to deteriorate; and when adding 0.9907% garlic powder, only for reducing the sodium content from 0.827% to 0.1319%, sensory rejection of the hamburger begins to occur. In addition, a new sensory threshold is proposed, the favored acceptance threshold (FAT), defined as the stimulus intensity at which significant improvement in sensory acceptance of the product begins to occur. It was also found that by adding 0.96% garlic powder it is possible to reduce the sodium content from 0.827% to 0.3707% and improve the sensory acceptance of the product.

Volatilome of Chill-Stored European Seabass (Dicentrarchus labrax) Fillets and Atlantic Salmon (Salmo salar) Slices under Modified Atmosphere Packaging

Fish spoilage occurs due to production of metabolites during storage, from bacterial action and chemical reactions, which leads to sensory rejection. Investigating the volatilome profile can reveal the potential spoilage markers. The evolution of volatile organic molecules during storage of European seabass (Dicentrarchus labrax) fillets and Atlantic salmon (Salmo salar) slices under modified atmosphere packaging at 2 °C was recorded by solid-phase microextraction combined with gas chromatography-mass spectrometry. Total volatile basic nitrogen (TVB-N), microbiological, and sensory changes were also monitored. The shelf life of seabass fillets and salmon slices was 10.5 days. Pseudomonas and H2S-producing bacteria were the dominant microorganisms in both fish. TVB-N increased from the middle of storage, but never reached concentrations higher than the regulatory limit of 30–35 mg N/100 g. The volatilome consisted of a number of aldehydes, ketones, alcohols and esters, common to both fish species. However, different evolution patterns were observed, indicating the effect of fish substrate on microbial growth and eventually the generation of volatiles. The compounds 3-hydroxy-2-butanone, 2,3-butanediol, 2,3-butanedione and acetic acid could be proposed as potential spoilage markers. The identification and quantification of the volatilities of specific fish species via the development of a database with the fingerprint of fish species stored under certain storage conditions can help towards rapid spoilage assessment.