Shelf Life Assessment Research Articles

E-Nose and Olfactory Assessment: Teamwork or a Challenge to the Last Data? The Case of Virgin Olive Oil Stability and Shelf Life

Electronic nose (E-nose) devices represent one of the most trailblazing innovations in current technological research, since mimicking the functioning of the biological sense of smell has always represented a fascinating challenge for technological development applied to life sciences and beyond. Sensor array tools are right now used in a plethora of applications, including, but not limited to, (bio-)medical, environmental, and food industry related. In particular, the food industry has seen a significant rise in the application of technological tools for determining the quality of edibles, progressively replacing human panelists, therefore changing the whole quality control chain in the field. To this end, the present review, conducted on PubMed, Science Direct and Web of Science, screening papers published between January 2010 and May 2021, sought to investigate the current trends in the usage of human panels and sensorized tools (E-nose and similar) in the food industry, comparing the performances between the two different approaches. In particular, the focus was mainly addressed towards the stability and shelf life assessment of olive oil, the main constituent of the renowned “Mediterranean diet”, and nowadays appreciated in cuisines from all around the world. The obtained results demonstrate that, despite the satisfying performances of both approaches, the best strategy merges the potentialities of human sensory panels and technological sensor arrays, (i.e., E-nose somewhat supported by E-tongue and/or E-eye). The current investigation can be used as a reference for future guidance towards the choice between human panelists and sensorized tools, to the benefit of food manufacturers.

Value addition of tilapia (Oreochromis niloticus): Preparation of fillet and shelf-life assessment

Although tilapia is one of the most cultivated fish species in Bangladesh owing to its high growth rate, comparatively easy culture practices, higher survival rate and short culture period but low market preference marked it as a low-priced fish. Various approaches have been adopted to enhance consumer acceptability and ensure better use of tilapia, including the production of value-added products such as tilapia-prepared fillets, which attract increasing interest. Therefore, the current study was designed and carried out in order to prepare tilapia fillets and to estimate their shelf life at frozen (-18±20C) and refrigerated (4±10C) temperatures. Fillets were produced from tilapia collected from local fish markets of Sylhet city, Bangladesh with according to Good Manufacturing Practices (GMP) established by International Standards Organization (ISO) and packed in polyethylene bags. Proximate composition, total volatile base nitrogen (TVBN), peroxide value (PV), pH, total plate count (TPC) and sensory properties of fillets were analyzed to determine shelf-life. A portion of the fresh fillet sample was immediately analyzed and the remaining portions were preserved for up to 12 and 90 days at refrigerated and frozen storage temperatures, respectively. Results revealed that, at a definite interval of time, changes in the chemical, microbial and sensory attributes of tilapia fillets were found to be more pronounced in refrigerated storage conditions than fillets stored in frozen conditions. The shelf life of refrigerated and frozen tilapia fillet samples was 9 and at least 90 days, respectively, per the results of sensory, microbial and chemical evaluation.
 Res. Agric., Livest. Fish.8(2): 231-240, August 2021

Shelf-life assessment of energy banana bar using acceleration method with critical moisture content approach

The shelf-life of the product need to be evaluated according to the commercialization of the product. Shelf-life assessment of the product can be done using acceleration method (Accelerated Shelf-life Testing) with critical moisture content approach. This research used the acceleration method to predict the expired date of the energy bar based banana. This method required the data such as initial water content, critical moisture content, solid weight of the product, surface area of the packaging, permeability water vapor of the packaging, saturated water vapor pressure, and slope of the sorption isotherm curve. The result showed that the shelf life of banana bar products that was packaged using aluminium foil, aluma, and metalized plastics consecutively for 511.15; 458.72; and 80.95 days based on the acceleration method with the critical moisture content approach.

EVALUATION OF MANUAL FRUIT HARVESTERS AND STORABILITY CHARACTERISTICS OF HARVESTED SWEET ORANGE UNDER ORDINARY ROOM STORAGE CONDITION

Harvesting is considered as one of the crucial and critical activities in fruit production, handling and storage and market cycle. Traditional harvesting and post-harvest technique are responsible for deteriorating the fruit quality and shortening the postharvest shelf-life. Hand-picking by climbing tree, tree shaking and stick biting are most common practices for majority of the fruit orchards in Nepal that is risky, labour and time-intensive practices as well as affects market quality and nutritive value of the fruits. Therefore, there is a need for simple manual fruit harvesting tools suitable for smallholder farmers to replace the manual picking of citrus. Hence, a study was conducted to evaluate the performance of different available models of manual fruit harvester along with the evaluation of post-harvest quality (physiological loss of weight, fruit firmness, total soluble solids, acidity and rot incidence) and shelf-life assessment of those harvested fruits during storage under ordinary room condition for 26 days. Nine harvesting treatments were investigated as follows: a) Farmer practice-hand-picking (FPground), b) Farmer practice tree climbing (FPclimb), c) Hand-shaking of the tree branch (TS), d) Secateurs (SEground), e) Secateur + tree climb (SEClimb), f) Pole mounted cut and hold type picking shears (CH), g) Telescopic Long reach fruit picker (LRF), h) Fruit picker harvester with basket and cushion (PHB), i) Metal fruit picker with cotton bag (PC). The harvesting capacity of FPground, FPclimb, SEground, SEClimb, LRF, CH, PHB, PC and TS methods were 98.4±5.84, 57.52±12.43, 94.7±38.14, 49.05±5.73, 79.14±6.15, 75.08±12.44, 49.88±17.48, 52.27±11.47 and 63.12±22.27 kg/hr, respectively.. The harvesting output of CH and LRF type harvester was 29.03 (591 nos/hr) and 15.93% (531 nos/hr) higher than FPclimb practice (458 nos/hr) and that of PHB and PC method was 20.96 (362 nos/hr) and 6.11% (430 nos/hr) lower than FPclimb. Regarding storability characteristics, shelf-life was found better in SEground, SEClimb, CH, LRF than TS and FP practices.SE and CH method found effective in prolonging the average shelf-life and maintaining the quality of sweet orange compared to TS and FP. The button or calyx on the harvested fruit in SE, CH and LRF method help to control and delay the sap oozing, physiological loss of weight and lateral infection that maintain fruit firmness, prolong the shelf-life and minimize the fruit damage and rot incidence during ordinary storage. Based on our findings, hand-held secateur, cut and hold type harvester and long reach fruit picker (twist and turn) are recommended as appropriate harvesting tools for sweet orange fruit picking.

Soluble solids content monitoring for shelf-life assessment of table grapes coated with chitosan using hyperspectral imaging

Table grapes have a relatively short shelf-life and degradation rate due to pathogen infestation during postharvest storage. Chitosan (CTS) edible coatings offer a potential alternative for extending the shelf-life of fruit. The objective of this study was to explore the efficacy of CTS edible coatings on the shelf-life of table grapes by the application of hyperspectral imaging for non-invasive and rapid soluble solids content (SSC) monitoring. Table grapes were coated with CTS solutions (0.5%, and 1%, w/v), while the uncoated fruit served as controls. Spectral changes over storage days were investigated using principal component analysis (PCA), and principal component images were extracted to visualize the degradation evolution. Table grapes coated with edible coatings presented significant delays in SSC change and degradation process compared with uncoated fruit. Moreover, partial least squares regression (PLSR) combined with feature bands selected by competitive adaptive reweight sampling (CARS) provided the better performance for SSC prediction with R2 higher than 0.801 for the uncoated and coated grapes. Conclusively, hyperspectral imaging was capable of monitoring the evolution of SSC, and 1% CTS coating was more effective in extending the shelf-life and maintaining postharvest quality of table grapes.

A Super Stable Mutant of the Plant Protein Monellin Endowed with Enhanced Sweetness.

Sweet proteins are a class of proteins with the ability to elicit a sweet sensation in humans upon interaction with sweet taste receptor T1R2/T1R3. Single-chain Monellin, MNEI, is among the sweetest proteins known and it could replace sugar in many food and beverage recipes. Nonetheless, its use is limited by low stability and high aggregation propensity at neutral pH. To solve this inconvenience, we designed a new construct of MNEI, dubbed Mut9, which led to gains in both sweetness and stability. Mut9 showed an extraordinary stability in acidic and neutral environments, where we observed a melting temperature over 20 °C higher than that of MNEI. In addition, Mut9 resulted twice as sweet than MNEI. Both proteins were extensively characterized by biophysical and sensory analyses. Notably, Mut9 preserved its structure and function even after 10 min boiling, with the greatest differences being observed at pH 6.8, where it remained folded and sweet, whereas MNEI lost its structure and function. Finally, we performed a 6-month shelf-life assessment, and the data confirmed the greater stability of the new construct in a wide range of conditions. These data prove that Mut9 has an even greater potential for food and beverage applications than MNEI.

Assessment of Shelf Life and Quality of Biofertilizers using Tricalcium Phosphate as an Anticaking Agent and Aluminium Silicate as the Inert Carrier

Background: Bio-fertilizers are the substances which contain living microorganisms, when applied to soil, seeds and plant root these fertilizers increases soil fertility and promote growth of the plant. Biofertilizers help plants to utilize important mineral resources, phosphorous and nitrogen. Microorganisms like Rhizobacteria, fungi and algae which provide nutrient to the soil and which are produced commercially are known as biofertilizers. The microorganisms which present in biofertilizers are Rhizobium species, Pseudomonas species and Azospirillum species etc. These biofertilizers have potential to replace conventional chemical fertilizers. The quality of biofertilizers is utmost important as they have to be used by farmers and should work well when applied to the soil. It should not form clumps after preparation. In this study, anticaking property provided by tricalcium phosphate (TCP) to individual biofertilizer containing Pseudomonas, Rhizobium and Azospirillum respectively (each separately) was studied. Methods: In our study, we have used serial dilution and direct count method (CFU) for checking viability of live microorganism for 15, 30 and 90 days duration in respective biofertilizers in our laboratory. Different percentage viz 5%, 10%, 15% and 20% of tricalcium phosphate (TCP) was used in addition to aluminium silicate as an inert carrier.Conclusion: Our study has validated that all percentage (5%, 10%, 15% and 20%) of tricalcium phosphate (TCP) is reducing clump formation as compared to control with no TCP added. On the basis of plate count method (CFU result) 10% TCP is found to be optimum to be used as an anticaking agent for biofertilizer containing Pseudomonas, Rhizobium and Azospirillum respectively.

Packaging of beef fillet with active chitosan film incorporated with ɛ-polylysine: An assessment of quality indices and shelf life

In the current study, the effect on packaged beef fillets (1 × 5 × 8 cm) of using active chitosan film (1%) was investigated. The fillets were stored at 4 °C for 12 days, and the film contained ɛ-polylysine (ɛ-PL) (0.3, 0.6, and 0.9% w/w). Chemical, microbiological, sensory properties, and quality indices of the fillets were investigated. Added to these factors was an assessment of the influence of ɛ-polylysine incorporation on the optical, structural, barrier, and mechanical specifications (elongation at break and tensile strength) of chitosan films. Based on the findings, a significant difference among the corresponding values to thickness, color, water vapor permeability (WVP), and mechanical specifications between the treated films by ɛ-PL and untreated films were noted. In addition, higher values of thickness and tensile strength were correlated with ɛ-PL added active chitosan films while compared with control samples. Additionally, no significant differences regarding the proximate composition (including protein, moisture, and fat) among beef fillet samples were observed. In this regard, due to significantly lower levels of pH, TVB-N, and TBARS ɛ-PL in enriched films, this technique demonstrated some protective effects on beef fillets. Another observation was that lower levels of the total viable count, coliform, mold, yeasts, and higher sensory properties were significantly associated with samples with added ɛ-PL (0.9%). Therefore, adding ɛ-PL into chitosan films could be introduced as an effective technique to extend the shelf life of beef fillets and maintain their quality indices during refrigerated storage.

Quantitative and Predictive Modelling of Lipid Oxidation in Mayonnaise.

Food emulsions with high amounts of unsaturated fats, such as mayonnaise, are prone to lipid oxidation. In the food industry, typically accelerated shelf life tests are applied to assess the oxidative stability of different formulations. Here, the appearance of aldehydes at the so-called onset time, typically weeks, is considered a measure for oxidative stability of food emulsions, such as mayonnaise. To enable earlier assessment of compromised shelf-life, a predictive model for volatile off-flavor generation is developed. The model is based on the formation kinetics of hydroperoxides, which are early oxidation products and precursors of volatile aldehydes, responsible for off-flavor. Under accelerated shelf-life conditions (50 °C), hydroperoxide (LOOH) concentration over time shows a sigmoidal curvature followed by an acceleration phase that occurs at a LOOH-concentration between 38–50 mmol/kg, here interpreted as a critical LOOH concentration (CCLOOH). We hypothesize that the time at which CCLOOH was reached is related to the onset of aldehyde generation and that the characterization of the LOOH-generation curvature could be based on reaction kinetics in the first days. These hypotheses are tested using semi-empirical models to describe the autocatalytic character of hydroperoxide formation in combination with the CCLOOH. The Foubert function is selected as best describing the LOOH-curvature and is hence used to accurately predict onset of aldehyde generation, in most cases within several days of shelf-life. Furthermore, we find that the defining parameters of this model could be used to recognize antioxidant mechanisms at play.

Listeria monocytogenes Assessment in a Ready-to-Eat Salad Shelf-Life Study Using Conventional Culture-Based Methods, Genetic Profiling, and Propidium Monoazide Quantitative PCR

Listeriosis is almost entirely transmitted through foods contaminated with Listeria monocytogenes. Ready-to-eat foods present a particular challenge due to their long refrigerated shelf-life, not requiring any heat treatment before consumption. In this work, a shelf-life assessment of an industrially produced ready-to-eat salad was performed using conventional culture-based and molecular methods. L. monocytogenes isolates were confirmed and serogrouped using multiplex PCR, and genetic subtyping was performed by pulsed-field gel electrophoresis (PFGE). PMAxx-qPCR was used as an alternative method for L. monocytogenes quantification in foods. Salad samples were kept at 4 °C, 12 °C, and 16 °C for eight days and analysed. At 4 °C, acceptable results were obtained considering hygiene indicators, i.e., Enterobacteriaceae (ranging from 3.55 ± 0.15 log cfu/g to 5.39 ± 0.21 log cfu/g) and aerobic mesophilic colony counts (5.91 ± 0.90 log cfu/g to 9.41 ± 0.58 log cfu/g) throughout the study, but the same did not happen at 12 °C and 16 °C. L. monocytogenes culture-based quantification exhibited low numbers (<1 log cfu/g) for all temperatures. From 30 presumptive isolates, 10 (33.3%) were confirmed as L. monocytogenes with the majority belonging to serogroup IVb. PFGE subtyping showed that 7 of the 10 L. monocytogenes isolates had 100% of pulsotype similarity, suggesting a possible common contamination source. PMAxx-qPCR revealed a statistically higher L. monocytogenes quantification (>3 log cfu/g) when compared to the conventional culture-based method, suggesting viable but non-culturable forms. Taken together, results underline the need to combine conventional methods with more sensitive, specific, and rapid ones for L. monocytogenes assessment in ready-to-eat foods shelf-life studies to reduce the potential risk for consumers.

Assessment of chicken breast shelf life based on bench-top and portable near-infrared spectroscopy tools coupled with chemometrics

Abstract Objectives Near-infrared (NIR) spectroscopy is a rapid technique able to assess meat quality even if its capability to determine the shelf life of chicken fresh cuts is still debated, especially for portable devices. The aim of the study was to compare bench-top and portable NIR instruments in discriminating between four chicken breast refrigeration times (RT), coupled with multivariate classifier models. Materials and Methods Ninety-six samples were analysed by both NIR tools at 2, 6, 10 and 14 days post mortem. NIR data were subsequently submitted to partial least squares discriminant analysis (PLS-DA) and canonical discriminant analysis (CDA). The latter was preceded by double feature selection based on Boruta and Stepwise procedures. Results PLS-DA sorted moderate separation of RT theses, while shelf life assessment was more accurate on application of Stepwise-CDA. Bench-top tool had better performance than portable one, probably because it captured more informative spectral data as shown by the variable importance in projection (VIP) and restricted pool of Stepwise-CDA predictive scores (SPS). Conclusions NIR tools coupled with a multivariate model provide deep insight into the physicochemical processes occurring during storage. Spectroscopy showed reliable effectiveness to recognise a 7-day shelf life threshold of breasts, suitable for routine at-line application for screening of meat quality.

Development and shelf life assessment of millet cookies by means of nutritional and sensory evaluation characteristics

Development and shelf life assessment of millet cookies by means of nutritional and sensory evaluation characteristics

Shelf-life assessment of bread containing Cyperus rotundus rhizome aqueous extract with antimicrobial compounds identified by 1H-NMR

This study evaluated the effects of Cyperus rotundus rhizomes aqueous extract on the shelf life of wheat bread. The aqueous extract strongly inhibited the growth of Aspergillus niger (78%), Penicillium spp. (89%) Bacillus subtilis (95%) and Bacillus cereus (90%). The C. rotundus extract had no significant (p≥0.05) effect on the moisture content (44.2–45.7) and water activity (0.86–0.87) of the wheat bread, significantly (p<0.05) increasing the phenolic content from 7.22 to 37.95 mg g−1 and decreasing the pH from 6.12 to 5.11. Fungal growth was observed on the treated bread after 11 days at 30 °C compared to 4 days for the control bread. However, the addition of the aqueous extract of C. rotundus affected the sensory attributes of the wheat bread but the bread was still considered acceptable by the trained panellists. In conclusion, the aqueous extract of C. rotundus rhizomes is a potential natural alternative to synthetic preservatives to extend the shelf life of wheat bread with high consumer acceptability.

Quality and shelf life assessment of a new beverage produced from water kefir grains and red pitaya

In order to diversify the consumption of red pitaya, the objective of this study was to evaluate the shelf life of two formulations of non-alcoholic beverages fermented by water kefir using red pitaya and apple pulp as substrates. The beverages were stored at 7 °C for 28 days, with analyses every 7 days. The species of yeast and bacteria identified in the highest percentages were Brettanomyces bruxellensis and Liquorilactobacillus satsumensis. After 28 days of storage, the pitaya and the pitaya and apple fermented beverages showed a reduction of 9.15% and 5.25% in pH, an increase of 2.7 and 1.8 times in acidity, a reduction of 6.27% and 5.25% in the total soluble solids content and an increase of 2.5 and 1.9 times in alcohol content, respectively. The addition of apple pulp to the pitaya-fermented beverage enhanced the antioxidant capacity from 2.49 mMFe+2.100 mL-1 to 3.19 mMFe+2.100 mL-1 and the reducing capacity from 42.08 mgEAG.100 mL-1 to 62.01 mgEAG.100 mL-1. However, reductions in the bioactive activity of the beverages were observed during the storage time. Both formulations presented satisfactory scores in relation to all the sensory attributes evaluated. Therefore, red pitaya and apple can be used to produce a new functional beverage.

BREAD PRODUCED FROM COMPOSITE FLOURS USING Saccharomyces cerevisiae ISOLATED FROM LOCAL FERMENTED BEVERAGE (BURKUTU)

Composite flour/bread technology is an important area to be properly harnessed in food industries to help reduce the cost of wheat importation in Nigeria. In this study, bread produced from composite flours using Saccharomyces cerevisiae isolated from local fermented beverage (Burkutu) was investigated. Sugar fermentation, carbohydrate utilization and ethanol tolerance tests were carried out in identifying and characterizing the yeast isolates. Composite breads were produced from Wheat Flour (WF) (100%) and its blends with Rice Flour (RF) (40%), Plantain Flour (PF) (40%) and Cassava Flour (CF) (40%) using the straight dough method. The yeast survived in 25% glucose and 15% ethanol, suggesting its usefulness in industrial application. Loaf weights and loaf volumes of the composite bread samples ranged from 318.4 - 355.7 g, and 420.6 - 457.3 mL respectively, with 100% Wheat Bread ranking highest while Composite rice bread the least, using a significant difference of P&lt;0.05. The total yeast count recorded after 4 days showed 0.25 x 10-3 CFU/mL (100% W bread), 0.40 x 10-3 CFU/mL (W/R (bread), 0.21 x 10-3CFU/mL (W/P bread) and 0.32 x 10-3CFU/mL for W/C bread. Sensory assessment revealed that there was no significant difference (P&gt;0.05) in the bread samples analysed. Shelf life assessment of the bread samples at room temperature (26±1oC) within the first three days revealed no microbial growth/cell count. Bread produced from the incorporation of cassava with wheat flour was found to be acceptable, with insignificant variation when compared to bread made with 100% wheat flour.

Extra virgin Argan oils’ shelf-life monitoring and prediction based on chemical properties or FTIR fingerprints and chemometrics

In order to achieve a better understanding of the shelf-life behavior of extra virgin Argan oils (EVAO) during storage, the influences of storage periods, roasting process and packaging materials were studied. Those oils were extracted from roasted and unroasted kernels. The EVAO shelf life assessment was made by determining chemical properties (acidity, peroxide value, specific absorbances K232 and K270, tocopherol content, fatty-acids and sterol composition, and oxidative stability index) and by FTIR spectra. Sixty EVAO samples (30 roasted and 30 unroasted) were evaluated after production and then were packed in two glass bottle types (dark and clear), which resulted in 120 samples. They were stored under realistic storage conditions (ambient temperature) for two successive years and analysed 6-monthly. Chemometric data analysis was applied to study the shelf-life influence. PCA and PLS-DA, on either the chemical data or the FTIR spectra, allowed the discrimination between fresh and oxidized oils. The oil shelf-life was predicted by means of PLS regression. Thus, the time of storage after which the oil loses its extra virgin quality could be predicted. Finally, the potential of FTIR fingerprinting to quantify four physicochemical properties (i.e. acidity, PV, K232 and K270) during EVAO storage was established using PLS regression.

Static intermittent fed-batch production of bacterial nanocellulose from black tea and its modification using chitosan to develop antibacterial green packaging material

Bio-based active packaging using biodegradable polymers is in great demand in the market due to its environment-friendly perspective but having the issues of high production cost, processing and performance. This study offers an industrially significant approach for the development of low-cost and eco-friendly bacterial nanocellulose (BNC) films using static intermittent fed-batch (SIFB) technology from low-cost medium i.e., fermented black tea. These BNC films were modified with a biopolymer–chitosan by simple immersion technique and analyzed for its usage as green and improved sustainable packaging material. After fermentation, the BNC was harvested, purified and oven-dried to obtain dry films. The results indicated a commendable BNC production of 29.2 gL-1 with the 63.2% substrate conversion to the BNC which was almost double than that obtained with a conventional static method (32%). The films were characterized using field emission scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetric analysis. The antibiotic susceptibility test showed an inhibition zone of 40 ± 1 mm and 37 ± 3 mm for Escherichia coli and Aerococcus viridans, respectively for BNC-chitosan nano-biocomposite films showing their potential as an active packaging material. The presence of chitosan in the film is responsible for its antibacterial nature that might have caused cell wall lysis or inhibited protein synthesis in bacteria. Besides this, it’s good mechanical strength, crystalline nature, resistance to air and shelf life assessment of tomatoes showed the great potential of BNC-chitosan films to be used for low-cost active packaging, which is incalculably demanded by the packaging industry.

Potential use of vegetable proteins to reduce Brazil nut oil oxidation in microparticle systems

Brazil nut oil is mostly composed of unsaturated fatty acids, some of which are associated with decreased incidence of cardiovascular diseases. Vegetable proteins have been increasingly used as wall material for partial replacement of carbohydrates and whey proteins. In order to create an oil preservation method, Brazil nut oil was encapsulated with three different types of vegetable protein concentrates and gum arabic (GA): rice (RPC + GA); pea (PPC + GA); and soy (SPC + GA) .For this purpose, vegetable protein concentrates were characterized, and after the drying process the physicochemical characteristics of the microparticles were evaluated. The most stable emulsion, after seven days of evaluation, was composed of RPC + GA. RPC + GA. This treatment was also more stable based on the shelf life assessments. We concluded that RCP microparticles were the best option for encapsulating Brazil nut oil in comparison with the other particles evaluated. In addition, the product obtained is potentially capable of being included in various processed foods.

Shelf life assessment of fresh green pesto using an accelerated test approach

Abstract The shelf life of fresh green pesto, a traditional Italian sauce, was determined by analysing the evolution of the most important chemical, physical, microbiological and sensory quality attributes during its refrigerated storage at 4, 8 and 12 °C. Colour changes (greenness parameter a*) were fitted by applying an apparent zero-order equation, thus showing strong dependence on temperature. Peroxide values (PV) and thiobarbituric acid (TBA) values, fitted by applying an apparent first-order equation, increased with increasing storage time. The sensorial results were the most restrictive criterion, rather than microbial spoilage, and their shelf life values at ±95 % confidence limits were calculated from Weibull's distribution. Taste and overall acceptability scores of fresh green pesto showed high correlation with PV. The temperature dependence of quality deterioration was adequately modelled by the Arrhenius equation. The Q10 value (shelf-life at T°C/shelf-life at T+10 °C) and Ea (activation energy) for PV deterioration of fresh pesto sauce were 3.2 and 77 kJ/mol, respectively. Correlation between a chemical indicator parameter (PV) and sensory probability of product failure was evaluated, and a shelf life plot of fresh green pesto was obtained in order to estimate the shelf life of the product at different refrigerated storage conditions.

Holistic Approach to the Uncertainty in Shelf Life Prediction of Frozen Foods at Dynamic Cold Chain Conditions.

Systematic kinetic modeling is required to predict frozen systems behavior in cold dynamic conditions. A one-step procedure, where all data are used simultaneously in a non-linear algorithm, is implemented to estimate the kinetic parameters of both primary and secondary models. Compared to the traditional two-step methodology, more precise estimates are obtained, and the calculated parameter uncertainty can be introduced in realistic shelf life predictions, as a tool for cold chain optimization. Additionally, significant variability of the real distribution/storage conditions is recorded, and must be also incorporated in a kinetic prediction scheme. The applicability of the approach is theoretically demonstrated in an analysis of data on frozen green peas Vitamin C content, for the calculation of joint confidence intervals of kinetic parameters. A stochastic algorithm is implemented, through a double Monte Carlo scheme incorporating the temperature variability during distribution, drawn from cold chain databases. Assuming a distribution scenario of 130 days in the cold chain, 93 ± 110 days remaining shelf life was predicted compared to 180 days assumed based on the use by date. Overall, through the theoretical case study investigated, the uncertainty of models’ parameters and cold chain dynamics were incorporated into shelf life assessment, leading to more realistic predictions.