Shelf Life Assessment Research Articles

The STARTEC Decision Support Tool for Better Tradeoffs between Food Safety, Quality, Nutrition, and Costs in Production of Advanced Ready-to-Eat Foods.

A prototype decision support IT-tool for the food industry was developed in the STARTEC project. Typical processes and decision steps were mapped using real life production scenarios of participating food companies manufacturing complex ready-to-eat foods. Companies looked for a more integrated approach when making food safety decisions that would align with existing HACCP systems. The tool was designed with shelf life assessments and data on safety, quality, and costs, using a pasta salad meal as a case product. The process flow chart was used as starting point, with simulation options at each process step. Key parameters like pH, water activity, costs of ingredients and salaries, and default models for calculations of Listeria monocytogenes, quality scores, and vitamin C, were placed in an interactive database. Customization of the models and settings was possible on the user-interface. The simulation module outputs were provided as detailed curves or categorized as “good”; “sufficient”; or “corrective action needed” based on threshold limit values set by the user. Possible corrective actions were suggested by the system. The tool was tested and approved by end-users based on selected ready-to-eat food products. Compared to other decision support tools, the STARTEC-tool is product-specific and multidisciplinary and includes interpretation and targeted recommendations for end-users.

Essential Oil of Fennel Seeds as Natural Preservative in Butter and its Shelf Life Assessment

Essential Oil of Fennel Seeds as Natural Preservative in Butter and its Shelf Life Assessment

Nutritional profiling and shelf life assessment of monosex tilapia steaks during ice storage

In freshwater aquaculture, monosex tilapia is emerging as a potential alternative to common tilapia which is a prolific breeder. The nutritional profile as well as the shelf-life stability of monosex tilapia stored under iced condition was assessed. The fatty acid profile pointed out that the major class of fatty acids present in tilapia was monounsaturated fatty acids (42.36%). Amino acid compositional analysis indicated higher levels of glutamic acid and aspartic acid. Tilapia steaks were divided into two lots for ice storage viz., control (AP: air packed) and vacuum packed (VP). AP samples crossed the total volatile base nitrogen (TVB-N) acceptability limit of 35 mg% towards 16th day of storage whereas VP samples were acceptable throughout the storage period of 19 days. Increase in thiobarbituric acid (TBA) value was more prominent in air packed lots during storage period. The decrease in hardness and lightness values were more prominent in vacuum packed samples. Results of the biochemical and microbiological analyses indicated that air packed samples were acceptable upto 16th day while it was extended to 19th day in vacuum packed samples.

Shelf life assessment of industrial durum wheat bread as a function of packaging system.

This study compared the effect of different packaging systems on industrial durum wheat bread shelf-life, with regard to thermoformed packaging (TF) and flow-packaging (FP). Two TFs having different thickness and one FP were compared by assessing physico-chemical and sensorial properties and volatile compounds of sliced bread during 90days of storage. Texture, aw and bread moisture varied according to a first-order kinetic model, with FP samples ageing faster than TFs. Sensorial features such as consistency, stale odor, and sour odor, increased their intensity during storage. Furans decreased, whereas hexanal increased. The Principal Component Analysis of the whole dataset pointed out that the TF system at reduced thickness could be adopted up to 60days, without compromising the standard commercial life of industrial bread and allowing to save packaging material. The FP system would allow further saving, but it should be preferred when the expected product turnover is within 30days.

Use of natural antimicrobials to improve the quality characteristics of fresh “Phyllo” – A dough-based wheat product – Shelf life assessment

This study explores the effects of chitosan and natamycin on the quality of fresh “Phyllo” – a dough-based wheat product, by monitoring the microbiological, physicochemical and sensory parameters. Four different lots of phyllo samples stored under aerobic packaging conditions, in the absence or presence of the aforementioned antimicrobials, were prepared and stored at 4 °C. Microbiological data suggested that, the combination of chitosan and natamycin resulted in significant reductions (1–3 log cfu/g) of the microbial species examined (mesophilic total viable counts; TVC), yeasts/molds, psychrotrophic and lactic acid bacteria (LAB), Enterobacteriaceae and coliforms) by day 10. The pH values of treated phyllo samples were lower on final day 10, as compared to the untreated phyllo, and of the Hunter color parameters (L*, b* and a*) that were evaluated, mostly the combined treatment of chitosan and natamycin maintained the original lightness (L*) and color (yellowness) stability (b*) of phyllo product during the storage period. Sensory data, based on overall acceptability (mean values of appearance and odor) scores confirmed the superiority of combined treatment of chitosan and natamycin, resulting in almost a doubling of the shelf-life of fresh phyllo, while retaining excellent sensorial characteristics (appearance and odor) even on final storage day (10).

Shelf-life prediction models for ready-to-eat fresh cut salads: Testing in real cold chain

The aim of the study was to develop and test the applicability of predictive models for shelf-life estimation of ready-to-eat (RTE) fresh cut salads in realistic distribution temperature conditions in the food supply chain. A systematic kinetic study of quality loss of RTE mixed salad (lollo rosso lettuce-40%, lollo verde lettuce-45%, rocket-15%) packed under modified atmospheres (3% O2, 10% CO2, 87% N2) was conducted. Microbial population (total viable count, Pseudomonas spp., lactic acid bacteria), vitamin C, colour and texture were the measured quality parameters. Kinetic models for these indices were developed to determine the quality loss and calculate product remaining shelf-life (SLR). Storage experiments were conducted at isothermal (2.5–15°C) and non-isothermal temperature conditions (Teff=7.8°C defined as the constant temperature that results in the same quality value as the variable temperature distribution) for validation purposes. Pseudomonas dominated spoilage, followed by browning and chemical changes. The end of shelf-life correlated with a Pseudomonas spp. level of 8 log(cfu/g), and 20% loss of the initial vitamin C content. The effect of temperature on these quality parameters was expressed by the Arrhenius equation; activation energy (Ea) value was 69.1 and 122.6kJ/mol for Pseudomonas spp. growth and vitamin C loss rates, respectively. Shelf-life prediction models were also validated in real cold chain conditions (including the stages of transport to and storage at retail distribution center, transport to and display at 7 retail stores, transport to and storage in domestic refrigerators). The quality level and SLR estimated after 2–3days of domestic storage (time of consumption) ranged between 1 and 8days at 4°C and was predicted within satisfactory statistical error by the kinetic models. Teff in the cold chain ranged between 3.7 and 8.3°C. Using the validated models, SLR of RTE fresh cut salad can be estimated at any point of the cold chain if the temperature history is known. Shelf-life models of validated applicability can serve as an effective tool for shelf-life assessment and the development of new products in the fresh produce food sector.

Monitoring olive oils quality and oxidative resistance during storage using an electronic tongue

Monitoring olive oils oxidative stability and quality parameters (free acidity, peroxide values, K232 and K270 extinction coefficients) is needed to guarantee that, during storage, their levels remain within the legal thresholds enabling their commercialization as high-value extra-virgin olive oils. Physicochemical levels are assessed using time-consuming routine analytical reference techniques. In this work, the feasibility of a novel approach that merges an electronic tongue and chemometric tools, for monitoring extra-virgin olive oils’ quality along one year of storage at dark or exposed to light is discussed. The results confirmed that physicochemical parameters varied with the storage lighting conditions and more significantly with time. Also, multiple linear regression models, using sub-sets of 22–28 sensors selected with a meta-heuristic simulated annealing algorithm, allow evaluating the storage time-evolution of olive oils’ peroxide values, extinction coefficients and oxidative stabilities with satisfactory accuracy (R2 ≥ 0.98 and ≥ 0.96, for leave-one-out and repeated K-fold cross-validation procedures, respectively). The capability of monitoring, in a single electrochemical assay, legal required quality parameters of olive oils, decreases considerable the analysis time and cost, allowing checking the compliance of extra-virgin olive oil quality with labeling. So, the use of electronic tongues for extra-virgin olive oil shelf-life assessment could be envisaged.

Optimization of time-electric field combination for PPO inactivation in sugarcane juice by ohmic heating and its shelf life assessment

The effect of ohmic heat (OH) treatment was measured on polyphenol oxidase (PPO) activity in sugarcane juice under different electric field strengths (24, 32 and 48 V/cm) and holding times (0.25, 0.50, 0.75, 1.0, 1.25 min) at a temperature of 80±2 °C, optimized by conventional thermal (CT) treatment. The optimum temperature of PPO inactivation for CT-treatment was determined in a parallel study. The processing condition of 32 V/cm and 1 min holding time was found optimum and was analyzed for titrable acidity (TA), reducing sugars (RS), ascorbic acid (AA) and microbial load for 10 and 30 days at room and refrigeration temperatures respectively. During refrigerated storage, TA and RS remained significantly (p<0.01) unchanged and the AA degradation was more pronounced at room temperature. Both treatments resulted in significant microbial reductions but growth resurfaced after 5th and 25 th day of room and refrigeration storage respectively. No yeast and mold growth was witnessed after OH-treatment. Overall, the OH-treatment was found to inhibit PPO enzyme activity in a shorter processing time than CT, while maintaining the potential quality attributes of the juice.

Assessment of storage shelf life of European squid (cephalopod: Loliginidae, Loligo vulgaris) by bioelectrical impedance measurements

The aim of this study was to examine the possibility of storage shelf life assessment of refrigerated squid Loligo vulgaris by bioelectrical impedance measurements.Fresh squid samples were kept in the refrigerator at 4 ± 1 °C during the period of 15 days and were examined every two days, starting on the 4th day post-mortem. The Agilent 4294A Precision Impedance Analyzer with needle-type multi electrode array arranged in bipolar configuration was used to measure impedance magnitude (|Z|) and phase (φ) at 200 frequencies from 100 Hz to 100 MHz. Protein solubility, color parameters and textural parameters have also been determined.Results showed that impedance (phase), color (a*) and protein solubility were highly correlated with the duration of storage, while texture parameters showed only moderate correlation. The correlation between phase and protein solubility was moderate until phase and texture parameters showed no correlation. The phase (φ) measured at 1 MHz showed a potential for the assessment of storage shelf life of the refrigerated European squid by grouping the samples into 3 distinctive groups post rigor mortis.

Shelf-Life Assessment of Agar Plates Vacuum-Sealed in Nylon/Polyethylene Packaging Flushed with Nitrogen

In resource-limited nations, enhancing the shelf-life and stability of critical reagents and consumables is desired. This study evaluated the shelf-life of bacteriological plates in vacuum-sealed nylon/polyethylene packaging flushed with nitrogen (FlatPacks®). Tryptic soy agar (TSA) FlatPacks held at room temperature for 24 months did not change in appearance or texture and supported bacterial growth similar to Day 0 concentrations. In contrast, TSA plates from a different supplier (Vendor A) desiccated after 4 months of storage at room temperature. TSA, blood agar (BA), and chocolate agar (CA) FlatPacks subjected to desert-like storage and transport temperatures (60 °C) for 30 days supported bacterial growth similar to FlatPacks held at room temperature or refrigerated; TSA, BA, and CA plates (Vendor A) desiccated within 7 days. The data suggest FlatPacks extend the shelf-life of TSA stored at room temperature when compared to traditional packaging. Additionally, TSA, BA, and CA FlatPacks support bacterial growth for at least 30 days when stored at 60 °C. Based on the results of this study, the FlatPacks may help laboratories in resource-limited nations overcome infrastructure, refrigeration, and supply-chain deficiencies.

Modelling and predicting growth of psychrotolerant pseudomonads in milk and cottage cheese

Mathematical models were developed and evaluated for growth of psychrotolerant pseudomonads in chilled milk and in cottage cheese with cultured cream dressing. The mathematical models include the effect of temperature, pH, NaCl, lactic acid and sorbic acid. A simplified cardinal parameter growth rate model was developed based on growth in broth. Subsequently, the reference growth rate parameter μref25°C-broth of 1.031/h was calibrated by fitting the model to a total of 35 growth rates from cottage cheese with cultured cream dressing. This resulted in a μref25°C-cottage cheese value of 0.621/h. Predictions from both growth rate models were evaluated by comparison with literature and experimental data. Growth of psychrotolerant pseudomonads in heat-treated milk (n=33) resulted in a bias factor (Bf) of 1.08 and an accuracy factor (Af) of 1.32 (μref25°C-broth), whereas growth in cottage cheese with cultured cream dressing and in non-heated milk (n=26) resulted in Bf of 1.08 and Af of 1.43 (μref25°C-cottage cheese). Lag phase models were developed by using relative lag times and data from both the present study and from literature. The acceptable simulation zone method showed the developed models to successfully predict growth of psychrotolerant pseudomonads in milk and cottage cheese at both constant and dynamic temperature storage conditions. The developed models can be used to predict growth of psychrotolerant pseudomonads and shelf life of chilled cottage cheese and milk at constant and dynamic storage temperatures. The applied methodology and the developed models seem likely to be applicable for shelf life assessment of other types of products where psychrotolerant pseudomonads are important for spoilage.

Use of TD-GC–TOF-MS to assess volatile composition during post-harvest storage in seven accessions of rocket salad (Eruca sativa)

An important step in breeding for nutritionally enhanced varieties is determining the effects of the post-harvest supply chain on phytochemicals and the changes in VOCs produced over time. TD-GC–TOF-MS was used and a technique for the extraction of VOCs from the headspace using portable tubes is described. Forty-two compounds were detected; 39 were identified by comparison to NIST libraries. Thirty-five compounds had not been previously reported in Eruca sativa. Seven accessions were assessed for changes in headspace VOCs over 7days. Relative amounts of VOCs across 3 time points were significantly different – isothiocyanate-containing molecules being abundant on ‘Day 0’. Each accession showed differences in proportions/types of volatiles produced on each day. PCA revealed a separation of VOC profiles according to the day of sampling. Changes in VOC profiles over time could provide a tool for assessment of shelf life.

Pharmacopoeial constants as indication of stability of polyherbal formulations – a study on Hutabhugadi and Sitopaladi Curna of Ayurvedic Formulary of India

Nowadays herbal medicines are popular all over the world. Drawback is consistency in the quality of the product over a range of time. Any considerable changes in the quality of the product over a time must be detectable. So stability testing is needed to ensure the quality of herbal products which is an evidence for the quality of the finished product. Present study reports the deviation in Pharmacopoeial constants of Hutabhugadi curna (HC) and Sitopaladi curna (SC) when stored at a recommended storage conditions and examined for a period of time. The variation in the Pharmacopoeial physico-chemical constants of the curna (fine powder) was observed during 0 (initial), 3rd and 6th month. Average shelf life is proposed for HC and SC based on 10% variation in physico-chemical tests specified in pharmacopoeia while compared to initial value. It was found that HC showed average ±10% variation in the values at 11.41 months while SC showed it at 22.58 months. This method of shelf life assessment can be used as routine shelf life check for polyherbal herbal formulations though this method is not bioavailability based assay applicable for single herb formulations.

Development of Quality Index Method Scheme for Common Carp (Cyprinus carpio) Stored in Ice: Shelf-Life Assessment by Physicochemical, Microbiological, and Sensory Quality Indices

ABSTRACTSensory methods are the most interesting methods to estimate fish quality. Among these, the recently developed quality index method (QIM) has gained popularity, as shown by the multiple publications of QIM schemes in the last years. The objective of this study was to create a new QIM scheme (QIM sensory table and corresponding point system) for the common carp (Cyprinus carpio), basing the definition of the rejection point on sensory, physicochemical (thiobarbituric acid reactive substances, total volatile basic nitrogen, pH, and color measurements), and microbiological criteria (counts of mesophiles, psychrotrophs, and Pseudomonas spp.). A new QIM scheme was developed and is proposed for use in the future; it will be useful for practical evaluations of carp freshness in all steps of the production chain, and it will contribute to a more effective use of the species as an alternative for human food supply.

Shelf-life Assessment of Food Undergoing Oxidation–A Review

Oxidation is the most common event leading to the end of shelf life of microbiologically stable foods. Thus, a reliable shelf-life assessment is crucial to verify how long the product will last before it becomes oxidized to an unacceptable level to the consumers.Shelf-life assessment strategies of foods and beverages suffering oxidation are critically discussed focusing on definition of the acceptability limit, as well as the choice of the proper oxidative indicators, and methodologies for shelf-life testing. Testing methodologies for shelf-life determination under actual and accelerated storage conditions are considered, highlighting possible uncertainties, pitfalls, and future research needs.

Development of a colorimetric sensor array for squid spoilage assessment

The aim of this work was to develop and evaluate a rapid, easy-to-use optoelectronic system for the shelf-life assessment of squid in cold storage. For this purpose, an optoelectronic nose was designed, which consisted of an array containing six sensing materials prepared by combining different dyes and two inorganic supports (aluminium oxide and silica gel). Samples were packaged with the colorimetric array and kept in cold storage for 12days. Squid spoilage was monitored simultaneously by the colorimetric array and by the physico-chemical and microbial analyses during storage. Samples exceeded the acceptability limits for microbial counts on the third day. PCA analysis carried out with CIELab showed that the colorimetric array was able to discriminate between fresh squid fit for consumption and spoiled squid. The statistical models obtained by PLS, with the optoelectronic nose, successfully predicted CO2 and O2 content in the headspace as well as microbial growth.

A Predictive Model for Listeria monocytogenes in UHT Dairy Products with Various Fat Content during Cold Storage

AbstractThe growth of Listeria monocytogenes was determined in Ultra‐High‐Temperature (UHT) dairy products (2% milk, 12 and 30% cream) at temperature range of 3–15C. Microbiological data were fitted to primary models (the Baranyi model, the modified Gompertz and logistic functions). The goodness‐of‐fit of primary models was analyzed by calculating mean square error and Akaike's information criterion. Baranyi model yielded the most accurate adjustment and the growth rates generated by this model were used for further mathematical analyses. Analysis of variance was used to check if the fat content significantly (P &lt; 0.05) influences the behavior of L. monocytogenes. No statistical differences were noted in the behavior of the pathogen. Microbiological growth data were combined and secondary modeling was performed using Ratkowsky, Arrhenius and polynomial models. The latter model gave the best description and was further validated using accuracy (Af) and bias (Bf) factors, as well as data from ComBase database and COMBASE Predictor.Practical ApplicationsMathematical models that describe the behavior of microorganisms, especially foodborne pathogens, in a particular product or group of food products with similar characteristics, pose a perspective of using predictive microbiology in order to increase the food safety. Application of predictive models is in agreement with Codex Alimentarius Commission and UE regulations in a risk analysis area. Presented results can be used by food manufacturers in food product development process, as well as a tool to support food safety assurance systems. Moreover, predictive models find practical application in Hazard Analysis and Critical Control Point (HACCP) plans providing useful information on the determination of critical control points (CCPs) and the estimation of critical limits at CCPs. The assessment and management of safety, quality and shelf life of food products can be facilitated by application of mathematical predictive models.

Assessment of shelf life of Bulgarian industrial FAME by the use of modified ASTM D2274 as accelerated oxidation method

Kinetic data for hydroperoxide formation in a commercial biodiesel, produced from 50% sunflower oil and 50% rapeseed oil were obtained by using rapid, higher than standard temperature procedure with sufficient oxygen solubility in the samples. Three different mathematical methods for processing the data and shelf life determination of the studied biodiesel are compared. The applicable methodologies are hydroperoxide concentration abrupt increase graphical determination and Q rule. The calculation shows that shelf life of the studied stabilized Bulgarian biodiesel amounts between 1.17 and 1.27years. It was also found that peroxide value for induction period at 15°C is 71.8meqO2/kg biodiesel.

Shelf-life and sensory assessments reveal the effects of storage treatments with 1-methylcyclopropene on new and established apples

Stanich, K., Cliff, M. A., Hampson, C. R. and Toivonen, P. M. A. 2014. Shelf-life and sensory assessments reveal the effects of storage treatments with 1-methylcyclopropene on new and established apples. Can. J. Plant Sci. 94: 1427–1439. This research used shelf-life and sensory assessments to explore the influence of 1-methylcyclopropene (1-MCP) on four apples (Aurora, Fuji, Nicola™, Salish™). Maturity (internal ethylene concentration, starch clearing index), quality (soluble solids, titratable acidity, firmness) and sensory determinations were conducted on fruit that had undergone air (AIR) or controlled atmosphere (CA) storage treatments with and without 1-MCP. Trained panelists evaluated apples, along with industry standards (Gala, McIntosh and either Fuji or Ambrosia), for eight attributes (crispness, hardness, juiciness, skin toughness, sweetness, tartness, sweet–tart balance and flavour). Data were analyzed using analysis of variance and principal component analyses (PCA) to compare the treatment and cultivar responses. Cultivars responded very differently to CA and 1-MCP. Fruit from AIR with 1-MCP were very similar to CA fruit without 1-MCP; further improvements were not observed when 1-MCP was applied to CA fruit. PCA bi-plots of the shelf-life and sensory assessments revealed that treated Salish™ fruits were more similar to one another than to cultivars from other treatments. This work successfully documented the unique changes associated with the use of 1-MCP on new and established apple cultivars. It will assist industry in applying appropriate storage practices for new and established apple cultivars.

Development of a Banana-based “Payasam Mix”

KEYWO RDS Ne ndra n. Reconstituted. Organoleptic Evalu ation. Proximate Composition. Yield. Overa ll Acceptability ABSTRACT Banana is grown in all kinds of soils having good drainage. This fruit has great socio-economic significance and is interwoven in the cultural heritage of the country. Of all the varieties, 'Nendran' is the most prized cooking variety used in Kerala In the context of low productivity of 'nendran', there is need for value addition to this crop. Jaggery based 'payasam' is an inevitable item for any festive occasion to a Malayali or for that matter, any South Indian. Owing to its cumbersome preparation, many housewives put off the preparation and prefer to make milk based which is easier to prepare. Standardisation and shelf life assessment of the product has been conducted in this study. Five samples of payasam mix were developed and reconstituted using standard procedures. Sample S1 scored highest with respect to sensory parameters. Its nutrient composition was ascertained and shelf life was also observed to be of high quality till 15 th day without addition of preservatives.