Shelf Life Evaluation Research Articles

Reduction in sodium content of fresh, semihard Tzfat cheese using salt replacer mixtures: taste, texture and shelf life evaluation

Tzfat cheese is a semihard, fresh cheese commonly produced in Israel, with an average sodium content of 1000 mg/100 g cheese. Reduction in sodium levels by 30% and 50% (w/w) with and without salt replacer mixtures was assessed in terms of cheese physicochemical, microbiological and sensory properties. Cheese, containing 30% KCl and 70% NaCl had the closest taste profile to the control cheese, according to electronic tongue analysis. All cheeses underwent a similar increase in extent of proteolysis and microbial growth during shelf life. This study demonstrates the possibility of reducing the sodium content in fresh, semihard cheeses like Tzfat cheese by more than 30% using salt replacer mixtures, without significantly affecting quality.

Evaluation of extra-virgin olive oils shelf life using an electronic tongue—chemometric approach

Physicochemical quality parameters, olfactory and gustatory–retronasal positive sensations of extra-virgin olive oils vary during storage leading to a decrease in the overall quality. Olive oil quality decline may prevent the compliance of olive oil quality with labeling and significantly reduce shelf life, resulting in important economic losses and negatively condition the consumer confidence. The feasibility of applying an electronic tongue to assess olive oils’ usual commercial light storage conditions and storage time was evaluated and compared with the discrimination potential of physicochemical or positive olfactory/gustatory sensorial parameters. Linear discriminant models, based on subsets of 5–8 electronic tongue sensor signals, selected by the meta-heuristic simulated annealing variable selection algorithm, allowed the correct classification of olive oils according to the light exposition conditions and/or storage time (sensitivities and specificities for leave-one-out cross-validation: 82–96 %). The predictive performance of the E-tongue approach was further evaluated using an external independent dataset selected using the Kennard–Stone algorithm and, in general, better classification rates (sensitivities and specificities for external dataset: 67–100 %) were obtained compared to those achieved using physicochemical or sensorial data. So, the work carried out is a proof-of-principle that the proposed electrochemical device could be a practical and versatile tool for, in a single and fast electrochemical assay, successfully discriminate olive oils with different storage times and/or exposed to different light conditions.

Shelf-life evaluation of virgin olive oil extracted from olives subjected to nonthermal pretreatments for yield increase

Abstract Critical process parameters for the yield and quality of olive oils are the temperature and treatment duration of the malaxation process. A balance between oil yield and quality must be achieved. Novel technologies such as High Pressure (HP) and Pulsed Electric Fields (PEF) that cause alterations to cell permeability, may promote the olive oil extraction process during malaxation, resulting in higher oil yields. Three different varieties of Olive fruits (Tsounati, Amfissis and Manaki var.) were subjected to different HP (200 and 600 MPa, 25 °C for 1 and 5 min) and PEF (1.6–70.0 kJ/kg) process conditions before malaxation (30 min at 30 °C). The extraction yield was increased up to 18 and 16% for PEF and HP treated olive fruits, respectively. The shelf-life tests indicate that the oil quality from nonthermally pretreated olives is dependent on the technology and process conditions used. An increase of oil oxidative stability for PEF and HP treated olives was shown, compared to control samples. The results show that HP and PEF could be applied for the production of superior quality virgin olive oil with increased yield.

Shelf Life Evaluation of Ricotta Fresca Sheep Cheese in Modified Atmosphere Packaging.

Ricotta fresca cheese is the product of Sardinian dairy industry most exposed to microbial post-process contamination. Due to its technological characteristics, intrinsic parameters, pH (6.10-6.80) and water activity (0.974-0.991), it represents an excellent substrate for the growth of spoilage and pathogenic microorganisms, which are usually resident in cheese-making plants environments. Generally, ricotta fresca has a shelf life of 5-7 days. For this reason, at industrial level, modified atmosphere packaging (MAP) is used to extend the durability of the product. However, few investigations have been conducted to validate the use of MAP in ricotta fresca. The aim of this work is to evaluate the shelf life of ricotta fresca under MAP. A total of 108 samples were collected from three Sardinian industrial cheese-making plants and analysed within 24 h after packaging and after 7, 14 and 21 days of refrigerated storage. Aerobic mesophilic bacteria, mesophilic and thermophilic cocci and lactobacilli, Enterobacteriaceae and E. coli, L. monocytogenes, Pseudomonas spp, Bacillus cereus, yeasts and moulds, and the chemical-physical parameters and composition of the product were determined. At the end of the shelf life, Pseudomonas spp. and Enterobacteriaceae reached high concentrations, 5 to 7 and 3 to 6 log10 colony forming unit g–1, respectively. The presence of environmental contaminants indicates that the use of MAP without the appropriate implementation of prerequisite programmes is not sufficient to extend the durability of ricotta fresca. Gas mixture and packaging material should be selected only on the basis of scientific evidence of their effectiveness.

7 A new, low-cost protein-to-creatinine strip dipstick to improve proteinuria screening for preeclampsia

Introduction Accurate and timely diagnosis of women at high risk for preeclampsia (PE) is key to accessing proper interventions and improving clinical outcomes. In collaboration with LifeAssay Diagnostics (LAD; South Africa), we have developed a new low-cost protein-to-creatinine (Pr/Cr) ratiometric strip test that improves the accuracy of proteinuria screening over the commonly-used protein-only dipstick by adjusting for urine dilution. Objectives Developmental efforts by PATH and its partners have focused on optimizing and evaluating the PrCr test characteristics to advance the prototype to downstream field validation and early introduction. Methods Performance evaluation : PATH and Magee Women’s Research Institute (USA) performed a laboratory-based evaluation of the LAD Pr/Cr test and the Siemens Multistix PRO LS, a commercial urinary dipstick that measures protein and creatinine but costs about US $7 per test. Each test was evaluated using 137 repository urine samples. Samples were selected across the capable dynamic range of the Pr/Cr test, based on protein and creatinine levels determined using a reference clinical laboratory analyzer. Usability : PATH, in collaboration with Kintampo Health Research Center (Ghana), conducted a field usability study with community antenatal care (ANC) providers. Data was collected through observation and interviews of 25 participants, including midwives and community health nurses, who performed and interpreted the test using urine control samples and multiple versions of prototype instructions. Thermal stability : A six-month longitudinal study is being conducted to evaluate both shelf-life stability of unopened product and in-use stability where the same product is repetitively opened over time. Three lots stored at 25 °C, 37 °C, and 45 °C were used for shelf-life evaluations, while the in-use stability study examined test performance on two manufacturing lots at either 25 °C or 45 °C. Results Performance evaluation : Compared to the reference standard assay, the LAD Pr/Cr dipstick demonstrated performance of 85% sensitivity and 71% specificity (95%CI) for proteinuria determination using a normal to abnormal cutoff of 0.19 Pr-to-Cr ratio. The Siemens Multistix demonstrated a 82% sensitivity and 79% specificity (95%CI). Usability : Participants found the test to be simple and easy to use. All participants accurately matched the color of the protein marker on the strip to the instructions, while 80% of participants correctly matched colors for the creatinine marker. Participants overwhelmingly preferred a linear test interpretation chart that outlines each possible permutation of Pr and Cr. Thermal stability : After four months, the Pr/Cr test strips demonstrated stable performance across all temperatures and manufacturing lots in both shelf-life and in-use stability testing. Conclusions The LAD Pr/Cr test provides a similar performance to the Siemens product as compared to the reference test at much lower cost comparable to the protein-only dipstick commonly used in low-resource countries. Other evaluation results indicate the test characteristics are compatible for field use. Additionally, the Pr/Cr test may offer additional advantages to the current protein-only dipstick in providing clearer interpretation to inform proper care.

Shelf Life Evaluation and Comparative HPTLC Profile of Hridya Yoga Churna

Shelf Life Evaluation and Comparative HPTLC Profile of Hridya Yoga Churna

Attempts to use photosensitization for preservation of strawberry cultivar ‘Darselect’: effects on shelf-life, nutritional and organoleptic properties” excluding Photosensitization for preservation of strawberry

The methods recently applied for decontamination of fruits and vegetables are not always efficient, human and ecologically friendly. In this context, photosensitization might serve as really promising tool. Obtained data indicated that Botrytis spp. was susceptible to photosensitization and its growth inhibited 14 % and reduced 18 % rotten strawberries. The following evaluation of shelf life of treated strawberries indicated some extension in comparison with control ones. The examination of nutritional quality of treated strawberries revealed that total antioxidant activity, amount of phenols and anthocyanins did not change in comparison with control. No effects on berry color were observed, just a slight reduction (10 %) of fruit firmness found in treated ones. In conclusion, photosensitization has potential as bio-fungicide, since inactivates Botrytis spp. on the surface of strawberry without impact on their nutritional properties or visual quality.

Evaluation of nutritive value and shelf life of strawberry genotypes

An investigation was carried out to evaluate the nutritive value and shelf life of five strawberry genotypes. It was found that under fresh condition the highest ascorbic acid (45.76 mg/100g) was obtained by Rabi-3 and the highest ?-carotene (15.09 IU/100g) by Festival. The maximum amount of reducing sugar (6.373 g/100g) and non-reducing sugar (2.947 g/100g) was recorded in Camarosa and Festival respectively. The maximum amount of calcium (0.480%) in BADC Strawberry, iron (93.50 ppm) in Rabi-3, phosphorus (0.081%) and potassium (0.854%) in BARI Strawberry-1 was recorded. Under different temperature and packaging conditions, polyethylene package at 40C proved to be superior to others in all respects. The highest shelf life (47.00 days) and ascorbic acid (42.76 mg/100g) after four days of storage was obtained by Camarosa in this condition; whereas the lowest shelf life (2.33 days) and ascorbic acid (10.12 mg/100g) was recorded in BADC Strawberry in plastic punnet package at 250C.Asian J. Med. Biol. Res. March 2016, 2(1): 19-26

Production and use of a flocculated paste of Nannochloropsis oculata for rearing newborn seahorse Hippocampus reidi

Rearing juvenile seahorses in green water system has been proven to be advantageous in comparison to clear-water. Although, on-farm produced microalgae can be expensive. Therefore, aquaculture farms are willing to replace fresh cultured microalgae for inert feed, as pastes. Despite their commercial availability, such pastes are expensive and their cells are unviable. A paste of the microalgae Nannochloropsis oculata (Eustigmatophycea) was produced through flocculation and stored it at 4°C for four weeks. The evaluation of shelf life was performed by measuring protein and carbohydrate content as well as the percentage of living cells and the possibility of using the paste as inoculum. The feasibility of substituting a fresh microalgae culture (FMC) and a commercial paste (CP) for the flocculated paste (FP) in the rearing juvenile seahorses Hippocampus reidi was analyzed. The ingestion rate, survival, and growth performance (height, length and dry weight) were evaluated. The seahorses were fed copepod Tisbe biminiensis offspring and newly hatched Artemia from the 2nd to 5th day after release (DAR), and from the 6th to 15th DAR, copepod offspring and enriched Artemia. The fatty acid profile of the microalgae was determined. The protein content of the FP remained constant, but the amount of carbohydrates was significantly lower after four weeks. The cells remained alive and able to reproduce after storage. No significant differences were found in ingestion rates, survival or dry weight, but the height and length of seahorses submitted to the FP and FMC treatments were significantly higher than those submitted to the CP. The FP and FMC exhibited live cells and higher percentages of highly unsaturated fatty acids in comparison to the CP. Thus, better results were obtained in the rearing of seahorses. In conclusion, the FP can be stored for four weeks, and can be used to replace FMC and CP.

Development and shelf-life evaluation of tomato-mushroom mixed ketchup.

This study reports on the possibility or suitability of ketchup preparation using mushroom pulp with tomato pulp. The pulp was extracted from mature and sound tomatoes and button mushroom (Agaricus bisporus L.) and subsequently used for preparation of Tomato-Mushroom ketchup. Different combinations of mushroom pulp with tomato pulp were made for ketchup preparation. The ketchup prepared with 50% tomato pulp and 50% mushroom pulp obtained highest organoleptic scores and was preferred than other treatments. The organoleptic score for ketch-up prepared by 100 % mushroom pulp was lowest. There was significant increase in protein, crude fibre and ash content whereas TSS, acidity, total sugars and vitamin C decreased significantly with increase in level of mushroom pulp. TSS increased significantly from 27.32 °B to 31.03 °B during storage for 12months. Whereas acidity value decreased from 2.22% to 2.10%. There was significant decrease in total sugars and increase in reducing sugars during storage at room temperature (RT). Vitamin C content also decreased significantly during storage. All these physico-chemical changes were less at refrigerated temperature (RFT) conditions. The mean value for overall sensory score decreased from 7.80 on zero days to 7.11 at RT and from 7.80 to 7.47 at RFT after 12months of storage. A significant increase in total plate count of ketch-up was observed during storage at room as well as at refrigerated temperature conditions. However this change was more at RT than RFT.

Fabrication of a sensitive gas sensor based on PPy/TiO2 nanocomposites films by layer-by-layer self-assembly and its application in food storage

An extra sensitive quartz crystal microbalance (QCM) gas sensor coated with thin PPy/TiO2 nanocomposite film was fabricated by using layer by layer self-assembly (SA) technology. The synthetic procedure and the resultant nanocomposites were characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FE-SEM). It was found that an ultra-sensitive PPy/TiO2 nanocomposite film with very thin layer can be successfully obtained by. It was also found that the number of deposited layers strongly impacted on sensor response with ten bilayers showing best sensor performance. The obtained gas sensor coating with PPy/TiO2 sensitive film was found to exhibit a better performance with respect to sensor responses, which is based on frequency data. The resultant sensor represented high sensitivity toward 10ppm of different targeted gases with evident frequency shift, fast response and recovery time. Long-term stability and excellent reversibility were also observed. In real-time application, a designed measurement set-up based on PPy/TiO2 based sensor showed a good ability on shelf-life evaluation of foodstuffs (mango, egg and fish). The resulting QCM based gas sensor coated with PPy/TiO2 nanocomposite via Layer by Layer self-assembly presented a promising capability to detect trace irritant gases and food quality evaluation.

Shelf Life and Quality Evaluation of Deep Frozen Coconut Cream, Coconut Scrapings and Coconut Slices

Coconut kernel is the major energy source in the diets of coconut producing countries. Ready to use coconut milk/kernel has a great demand in the market specifically for its nutty flavor. Studies were conducted to evaluate the storage quality of deep frozen coconut cream, scraped coconut and coconut slices. Coconut cream pasteurized and scraped coconut and coconut slices were blanched at 70 °C for 1.5 minutes. A known weight of each product was packed in nylon low density polyethylene, triple laminate and polyethylene and stored in a freezer at -18 °C. The shelf life was evaluated by free fatty acid content (FFA), peroxide value (PV) and total microbial load. The acceptability was tested using a triangle test with a 25 semi trained panelists in two weeks intervals for two months. FFA content increased during the storage period, but none of the products exceed the standard level of 1% The development of FFA in products packed in triple laminates was slow and peroxides were not detected up to 8 weeks of storage period. At the 8th week, microbial count reached to 106. Sensory study revealed that the organoleptic properties of all three coconut products were within the acceptable range though products showed differences sometimes, after 4 weeks storage compared with fresh samples. The results indicated that the minimum shelf life of the frozen coconut products is 8 weeks.

Influence of prebiotics on Lactobacillus reuteri death kinetics under sub-optimal temperatures and pH

Eaten foodstuffs are usually fortified with prebiotic ingredients, such as inulin and oligofructose (FOS). The main goal of this study was to evaluate the combined effects of inulin and FOS with either suboptimal pH or storage temperature on the viability of Lactobacillus reuteri DSM 20016. Data were modeled through Weibull equation for the evaluation of the microbiological shelf life and the survival time. Prebiotics enhanced the microbiological shelf life and enhanced the survival time of the target bacterium. The use of the factorial ANOVA highlighted that inulin and FOS exerted a different effect as a function of pH and temperature. Inulin prolonged survival time under acidic conditions, while the effect of glucose + FOS was significant at pH 8. Finally, temperature could act by increasing or decreasing the effect of prebiotics, as they could exert a protective effect at 30 °C but not at 44 °C. As the main output of this research, we could suggest that the effect of prebiotics on L. reuteri could be significantly affected by pH and temperature, thus pinpointing that the design of a symbiotic food should also rely on these factors.

Shelf life evaluation of Shirishavaleha: A preliminary study

Context: Shelf life of the drug can be considered up to the period it gets deteriorated and does not get any alteration in its physicochemical state. Every product has definite shelf life, which depends on various physical, chemical, environmental, and biological factors. Ancient seers have clarified shelf life of various compound formulations. However, there is a need to revalidate and ascertain the shelf life of individual formulations by following parameters prevalent in respective scenario. Aim: To evaluate shelf life of Shirishavaleha prepared in the presence of water (SW) and Kanji (SK) as liquid media through accelerated stability study. Subjects and Methods: Physicochemical parameters were measured at 40°C ± 2°C temperature and 75% ±5% relative humidity. Analysis was repeated at intervals of 1, 3, and 6 months, and average 10% degradation of both the test drug samples was calculated and extrapolated to find the shelf life. Results: The sample prepared in the presence of Kanji (SK) showed more extractive values and sugar contents and found to have longer shelf life (2.6 years) than SW (1.4 years). Conclusion: Shirishavaleha prepared with Kanji (SK) is comparatively more stable than the sample prepared with water (SW).

Studies on development and shelf life evaluation of soup powder prepared by incorporation of white button mushroom (Agaricus bisporus L.)

Studies on development and shelf life evaluation of soup powder prepared by incorporation of white button mushroom (Agaricus bisporus L.)

A Focus on the Death Kinetics in Predictive Microbiology: Benefits and Limits of the Most Important Models and Some Tools Dealing with Their Application in Foods.

Predictive Microbiology (PM) deals with the mathematical modeling of microorganisms in foods for different applications (challenge test, evaluation of microbiological shelf life, prediction of the microbiological hazards connected with foods, etc.). An interesting and important part of PM focuses on the use of primary functions to fit data of death kinetics of spoilage, pathogenic, and useful microorganisms following thermal or non-conventional treatments and can also be used to model survivors throughout storage. The main topic of this review is a focus on the most important death models (negative Gompertz, log-linear, shoulder/tail, Weibull, Weibull+tail, re-parameterized Weibull, biphasic approach, etc.) to pinpoint the benefits and the limits of each model; in addition, the last section addresses the most important tools for the use of death kinetics and predictive microbiology in a user-friendly way.

High Pressure Pasteurization of Sugarcane Juice: Evaluation of Microbiological Shelf Life and Quality Evolution During Refrigerated Storage

In this study, sugarcane juice subjected to both high-pressure processing (HPP) and thermal pasteurization (TP) was used to compare the changes in microbial levels, physicochemical properties, antioxidant capacity, sugar content, activity of sucrose neutral invertase, and sensory analysis during 28 days of refrigerated storage. Results showed that HPP treatment of 600 MPa and TP significantly reduced aerobic bacteria, coliform, and yeast counts. At day 28 of storage, HPP-treated juice (600 MPa/6 min) displayed no significant differences when compared to the fresh juice in terms of physicochemical properties such as total titratable acidity, pH, and total soluble solids. Although significant differences were observed in HPP-treated juice in color, antioxidants, and antioxidant capacity, the extent of the differences was substantially lower than that in thermal-treated juice, indicating that HPP treatment can retain better quality of sugarcane juice. After HPP treatment of 600 MPa and TP, invertase enzyme activity on day 7 declined to 87.69 and 82.86 %, respectively, which could possibly prevent sucrose conversion to fructose and glucose during refrigerated storage. Sensory testing showed no significant difference between HPP-treated juice and fresh juice, while TP reduced the acceptance of sugarcane juice. Collectively, this study indicated that HPP pasteurization can successfully reduce the microbial load in sugarcane juice. Meanwhile, HPP treatment maintains stable quality and inhibits enzyme activity, and thus, it can effectively extend shelf-life during refrigerated storage. Thus, HPP has a great potential in the development of drinks with fresh sugarcane juice.

Diverse postharvest responses of tomato fruits at different maturity stages to hot water treatment

Sensitivity of tomato fruits to chilling injury limits its storage and marketability. This study investigated the effect of hot water treatment (HWT) on reducing the consequences of chilling injury (CI) with respect to quality attributes of tomatoes during storage. Tomatoes were harvested at three ripening stages: mature green, pink, and red; dipped in hot water at 45°C for 15 min; and stored at three storage temperature conditions: 5°C, 13°C, and a simulated condition (SC: 3 days at 25°C and then at 5°C) representing the time between harvest and consumption by consumer. Quality analysis was carried out at the beginning of the experiment and every 10 days of storage 3 days of shelf life evaluation. Fruit color, lycopene content, weight loss, and CI were evaluated during the experiment. HWT reduced CI in mature green tomatoes but had little effect in pink and red fruits. It also caused delay in surface color development and reduced weight loss. During storage, heated mature green fruits often had significantly more lycopene content but low a* compared with unheated ones, whereas in heated red fruits, both a* and lycopene content were lower than unheated ones. This study showed that HWT could be used to reduce CI in mature green tomatoes, but not in pink and red fruits.

Evaluation of shelf-life of soy based weaning food using different packaging material

Over the recent decades, researchers have documented the health benefits of soy protein, especially for those who take soy protein daily. Soy products offer a considerable appeal for a growing segment of consumers with certain dietary and health concerns. Weaning foods were formulated by complementing with unsprouted and sprouted soybean at 0, 10 and 20 per cent level of fortification. Soy based weaning foods were packed in three different packaging materials i.e. LDPE, HDPE and LAF. Shelf-life was analyzed for chemical parameters including: moisture and free fatty acid (FFA) content at time intervals of 15 days and 90 days of storage at 30°C with 65 per cent relative humidity. During storage moisture and FFA content were increased. Free fatty acid content of unsprouted soybean supplemented weaning food significantly increased from 0.31 to 0.73 per cent whereas for sprouted soybean supplemented weaning food, values of FFA increased from 0.30 to 0.61 per cent. However, moisture content was increased with increase in storage period. The laminated aluminium foil (LAF) package was proved to be best packaging material for storage of soy based weaning food. The maximum shelf-life of the products was up to 90 days under the storage conditions studied.

Production and shelf life evaluation of storable myco-granules for multiple environmental applications

The present work describes a novel attempt to produce myco-granules targeted for multiple industrial applications including dye and heavy metal sequestration and xylanase production. Three low cost, locally available substrates FS1 (rice flour), FS2 (maize flour) and FS3 (wheat flour) were characterized and used for producing three myco-granules MG1, MG2 and MG3, respectively. Spore load of freshly prepared myco-granules and after 6 months of storage at 30 °C was estimated. MG1 exhibited least decrease (32%) in number of spores as compared to MG2 (40%) and MG3 (87%). Shelf-life studies conducted for different myco-granules stored at 4 °C, 30 °C and ambient temperature conditions show unaltered biomass production for the initial three months which rules out the need for controlled temperature conditions during storage. When stored at 30 °C, MG1 could remove 83% Acid Navy Blue dye, 57% Cu(II), >68% Cr(VI) (initial concentration 200 mg L−1 for dye and 50 mg L−1 for respective metals) and was able to produce 70.8 U g−1 crude xylanase activity through solid state fermentation after one year. The myco-granule MG1 has the potential of remediating wide varieties of wastewater containing dye and heavy metals as well as producing industrially important enzymes. Further, its prolonged shelf life under non-refrigerated conditions has highlighted its superiority over conventional means.