First Week Of Storage Research Articles

Gamma Radiation-Induced Effects on Riboflavin Epr Investigation and Spectroscopic Analyses

Electron paramagnetic resonance (EPR) spectroscopy was used to investigate the gamma radiation induced free radicals in the riboflavin (RF, vitamin B 2 ) and the behavior of the radicals upon radiation sterilization of RF. The physicochemical properties of RF subjected to γ-rays were also investigated by Fourier transform infrared (FTIR), X-ray diffraction (XRD) and ultraviolet-visible spectrophotometry (UV-Vis). The un-irradiated RF exhibits a very weak EPR signal (g = 2.00950) and upon γ-ray exposure the signal increases proportionally with increasing absorbed dose. The EPR signal of irradiated RF decays significantly during the first week of storage then tends to decrease slowly until the end of 100 days of storage period. It was reported also that no significant changes in the FTIR spectra, XRD pattern and UV-Vis spectra of RF dry samples were observed upon γ-ray exposure up to an absorbed dose of 50 kGy.

Polyacetylene levels in carrot juice, effect of pH and thermal processing

This research focuses on the study of polyacetylenes in carrot juice and their response to pH, storage and thermal processing conditions. Falcarindiol-3-acetate (FaDOAc) and falcarinol (FaOH) were in fresh carrot juice at concentrations of 73 and 233μg/L, respectively. Reducing the pH of the raw carrot juice from its natural pH 6.13 to pH 3.5 resulted in 2 and 5 fold better extraction of FaDOAc and FaOH respectively in comparison to a control sample (pH 6.13). Polyacetylenes were retained better in acidified juices and cold storage temperatures (4°C) for first week of storage with respect to untreated juices. An increase in FaDOAc and FaOH of 10- and 16-fold, respectively, as compared to raw unprocessed samples was observed when processing samples at 90°C for 1min. This was assumed to be due to cell wall polysaccharides dissolution. However, negative correlation between total polyacetylenes and hexoses was confirmed by 1H NMR spectroscopy, indicating some biological links between polyacetylenes and soluble sugars.

The effect of treating method of game on the content of biogenic amines in wild duck (Anas platyrhynchos) meat during the course of storage

The aim of present study was to assess the correlation between the method of treating the carcasses of shot wild ducks (Anas platyrhynchos) and the formation of biogenic amines in the their muscles. The carcasses of wild ducks (n = 180) were divided into three groups of 60 carcasses according to the method of treatment: eviscerated, drawn, and left untreated. Each group was further divided into three subgroups of 20 duck carcasses on the basis of the storage temperature (0, 7, and 15 °C) and stored for 21 days. Samples of breast and thigh muscles were taken at regular weekly intervals. Biogenic amines (cadaverine, putrescine, tyramine, histamine, phenylethylamine, and tryptamine) in samples of breast and thigh muscles were separated by reverse-phase liquid chromatography and detected by tandem mass spectrometry. The sum of biogenic amines was compared with a value of 5 mg/kg, indicating the critical content for fresh meat of high hygienic quality. The results of this study indicated that the sum of biogenic amines in wild duck meat exceeded this limit in an extremely short period of time after the commencement of storage (during the first week of storage). Higher content of biogenic amines were recorded in thigh muscle compared to breast muscle of drawn ducks and untreated ducks. According to our results, the generally recommended method for treating the carcasses of feathered game after hunting (evisceration) does not represent a method that would ensure a longer period of freshness or higher hygiene quality of the game than the other two possible methods of treatment from the biogenic amines point of view.

Physicochemical and functional properties of starches of two quality protein maize (QPM) grown in Côte d’Ivoire

Objective: The aim of this study was to investigate physico-chemical and functional properties of starches from two novel (white and yellow QPM) varieties of maize cultivated in Côte d’Ivoire in order to explore their potential use in food and non food industries.Methodology and results: Starches from four varieties of maize, namely two ordinary (white and yellow varieties) and two QPM (white and yellow varieties) were extracted and their physico-chemical and functional characteristics were determined. Statistical analyses were performed on data obtained. Protein and fat contents (0.35-0.37 ± 0.06%; 0.53-0.57 ± 0.05%) of white and yellow QPM starches were lower than that (0.38-0.39 ± 0.06%; 0.63-0.66 ± 0.05%) of white and yellow ordinary maize. The particle size of the four starches varied from 4.75 to 22.79 Bm for white QPM; 5.28 to 22.62 Bm for white ordinary maize; 5.98 to 22.88 Bm for yellow QPM and 5.63 to 21.47 Bm for yellow ordinary maize. Solubility white QPM starch showed the highest solubility (19.43%) and yellow QPM was characterized by highest value (20.39g/g) of swelling power. The percentage of water expelled from white QPM starch was 40.39% at -15°C and 37.05% at 4°C after the first week of storage while yellow QPM starch was characterized by syneresis values of 40.09% at -15°C and 36.92% at 4°C. The paste clarity of all starches decreased quickly during the first week and then stabilized at about 0.74 to 1%.Conclusions and application of findings: Starches from white and yellow QPM present better properties than ordinary maize and could be a valuable alternative for exploitation in food and non-food industries.Key words: QPM maize, starch, physicochemical characteristics, morphology, retrogradation.

The effect of treating method of pithed pheasant on the content of biogenic amines in the meat during the course of storage

The study monitored the effect of various methods of treating pheasant carcasses after killing on the hygienic quality of the venison. Pithed pheasants treated by evisceration (n = 60), drawing (n = 60), or left untreated (n = 60) were stored for a period of 21 d at temperatures of 0, 7, and 15°C. For determination of biogenic amines, samples of breast and thigh muscles were taken on d 1, 7, 14, and 21 after killing of the pheasants. Biogenic amines were separated by reverse-phase liquid chromatography and consequently detected by tandem mass spectrometry. The sum of determined biogenic amine concentrations (cadaverine, putrescine, histamine, tyramine, tryptamine, phenylethylamine) was compared with the value of the index for meat of high hygienic quality (5 mg/kg). At a storage temperature of 0°C, the sum of biogenic amine concentrations did not exceed the value of 5 mg/kg in either breast or thigh muscle at any time during the storage period in untreated and drawn pheasants, and for a period of 14 d in eviscerated pheasants. At a storage temperature of 7°C, values lower than the limit of 5 mg/kg were recorded throughout the storage period in untreated pheasants, for a period of 14 d of storage in drawn pheasants, and for a period of just 7 d of storage in eviscerated birds. At the highest storage temperature (15°C), a value of 5 mg/kg was exceeded in eviscerated and untreated pheasants during the course of the first week of storage, and in drawn pheasants after the first week of storage. Our results indicate that the most suitable method of treatment to ensure high hygienic quality of the meat (assessed according to concentration of biogenic amines) for the longest period during the storage of pithed pheasants is to leave the pheasant carcasses untreated, followed by the drawing, with the least suitable method being the widely recommended method of evisceration.

Effect of Freezing on Some Plant Toxins and Micronutrients in the Leaves of Amaranthus Cruentus

Postharvest handling isone of the major factors affecting the chemical contents of vegetables afterharvesting. It is for this reason that the study was conducted to determine theinfluence of freezing on some plant toxins (cyanide, nitrate, soluble and totaloxalates) and micronutrients which include vitamins (β-carotene and vitamin C)and mineral elements (Fe, Cu, Mg, Na and K) in Amaranthus cruentus. Theresults showed that the concentrations of vitamin C, β-carotene, K, cyanide,soluble and total oxalates in Amaranthus cruentus decreasedsignificantly (p < 0.05) during one week of freezing and they remainedsignificantly unchanged in the second, third and fourth weeks of freezing. Exceptthat the concentration of β-carotene in the fourth weeks was significantlylower than the second weeks of freezing. The decreasing effect of freezing onnitrate concentration in Amaranthus cruentus was not significant duringthe first week of storage, however, its concentration decreased significantly(p < 0.05) in the second weeks and the value remained significantlyunchanged for the third and fourth weeks of freezing. The significant decreasedin the concentrations of Fe and Cu during freezing was observed during threeweeks of freezing and remained significantly unchanged in the fourth weeks of storage.Similarly the concentrations of Mg and Na in Amaranthus cruentusdecreased significantly (p < 0.05) during two weeks of freezing and remainedsignificantly unchanged in the third and fourth weeks. The results concludethat although freezing significantly reduced the antinutrients and toxicsubstances in Amaranthus cruentus it has a deleterious effects on themicronutrients content of the vegetable.

Quality of fresh‐cut purple‐fleshed sweet potatoes after X‐ray irradiation treatment and refrigerated storage

SummaryThe effect of X‐ray irradiation on the quality of fresh‐cut, refrigerated purple‐fleshed sweet potato (PFSP) cubes was investigated. Packaged sweet potato cubes were treated with 0, 250, 500, 750 or 1000 Gy X‐ray irradiation and stored at 4 ± 1 °C for 14 days. After 14 days, total aerobic bacteria counts were 4.1 and 3.2 log10 CFU g−1, and mould–yeast counts were 3.3 and 3.0 log10 CFU g−1 in 750 and 1000 Gy treated samples, respectively. Doses up to 1000 Gy did not affect the firmness, moisture content and anthocyanin content of PFSP cubes throughout storage. PFSP cubes' flesh colour did not change during the first week of storage, but lightness (L*) increased after 14 days. Also, irradiation doses at 750 and 1000 Gy decreased saturation (C*) significantly, producing duller flesh colour than controls. Results indicate that X‐ray irradiation treatment at doses up to 1000 Gy can reduce microbial populations while maintaining the physical quality and anthocyanin content of PFSP cubes up to 14 days of storage.

Polyamine content during minimal growth storage of Thymus moroderi explants

The polyamine (PA) content of in vitro-grown explants of Thymus moroderi Pau ex Martinez has been evaluated during minimal growth storage. The growth restriction was imposed by the combined action of osmotically-active compounds (15 g dm−3 sucrose and 15 g dm−3 mannitol) present in the Murashige and Skoog medium and the modification of the physical environment of the culture (4 °C and darkness). In these conditions, cultures were maintained up to 29 weeks without subculture. During this storage period, we analyzed contents of free, perchloric acid (PCA)-soluble and PCA-insoluble conjugated PA. Minimal growth storage brought about an increase in free putrescine (Put) coinciding with a reduction in PCA-soluble conjugated Put occurring during the first weeks of storage. PCA-insoluble conjugated spermidine (Spd) also accumulated in response to storage.

The stability of markers in dried-blood spots for recommended newborn screening disorders in the United States

Objective We aimed to measure separately the contributions of heat and humidity to changes in levels of 34 markers of inborn disorders in dried-blood-spot (DBS) samples. Design and methods We stored paired sets of DBSs at 37 °C for predetermined intervals in low-humidity and high-humidity environments. Marker levels of all samples in each complete sample set were measured in a single analytic run. Results During the 30 ± 5 day studies, galactose-1-phosphate uridyltransferase and biotinidase lost almost 65% of initial activities in low-humidity storage; most of the degradation in 27 other markers was attributable to adverse effects of high-humidity storage; seven markers in DBSs stored at high humidity lost more than 90% of initial levels by the end of the study and 4 of the 7 lost more than 50% of initial levels within the first week of storage. Conclusions Minimizing both humidity and temperature in DBS transportation and storage environments is essential to maintaining sample integrity.

Incubation of curing brines for the production of ready-to-eat, uncured, no-nitrite-or-nitrate-added, ground, cooked and sliced ham

Salt concentration, vegetable juice powder (VJP) concentration and temperature were investigated to determine necessary conditions for incubation of curing brines including VJP and a starter culture containing Staphylococcus carnosus prior to production of naturally cured, no-nitrate/nitrite-added meat products. Subsequently, incubated brines were utilized to produce no-nitrate/nitrite-added sliced ham in which quality characteristics and residual nitrite concentrations were measured to determine feasibility of brine incubation for nitrate conversion prior to injection. Two ham treatments (one with VJP and starter culture; one with pre-converted VJP) and a nitrite-added control were used. No differences (P>0.05) were found for color in the VJP treatments. Control sliced ham was redder after 42days of storage, retaining significantly (P<0.05) greater a* (redness) than either of the VJP treatments. Residual nitrite concentration was greater (P<0.05) in the control hams during the first week of storage. While the nitrite-added control retained greater red color and initially had more residual nitrite than the VJP treatments, the two VJP treatments did not differ from each other.

Optimising fermentation of soymilk with probiotic bacteria

Soymilk was fermented with probiotic culture ABT5 and yoghurt culture with the addition of bifidobacteria at different temperatures (37&amp;deg;C and 42&amp;deg;C) with the aim of shortening the fermentation time and producing a probiotic fermented soymilk. During the fermentation and storage of the fermented soymilk (28 days at +4&amp;deg;C), the changes in pH-value and viable cells count were observed. Incubation temperature did not affect significantly fermentation time (7 h at 42&amp;deg;C and 8 h at 37&amp;deg;C, respectively), with ABT5 culture (Lactobacillus acidophilus, Bifidobacterium spp., and Streptococcus thermophilus). However, Lactobacillus acidophilus survived poorly during cold storage and the viable cells count was under the probiotic minimum as soon as after the first week of storage. Therefore in the consequent phase of the experiment, soymilk was fermented at 42&amp;deg;C with yoghurt culture YCX11 enriched with Bifidobacterium animalis subsp. lactis Bb12. Consequently, the fermentation time was shortened to 4 hours whereby the viable cells count of bifidobacteria increased during fermentation for the half of the logarithm scale approximately. During 28 days of cold storage, bacterial count remained constant and above 107 CFU/ml.

Anaerobic storage of red blood cells.

Anaerobic storage of red blood cells.

Is red blood cell rheology preserved during routine blood bank storage?

Red blood cell (RBC) units stored for more than 2 weeks at 4 degrees C are currently considered of impaired quality. This opinion has primarily been based on altered RBC rheologic properties (i.e., enhanced aggregability, reduced deformability, and elevated endothelial cell interaction), during prolonged storage of nonleukoreduced RBC units. In this study, the rheologic properties and cell variables of leukoreduced RBC units, during routine blood bank storage in saline-adenine-glucose-mannitol, were investigated. Ten leukoreduced RBC units were stored at the blood bank for 7 weeks at 4 degrees C. RBCs were tested weekly for aggregability, deformability, and other relevant variables. RBC aggregability was significantly reduced after the first week of storage but recovered during the following weeks. After 7 weeks aggregability was slightly, but significantly, reduced (46.9 + or - 2.4-44.3 + or - 2.2 aggregation index). During storage the osmotic fragility was not significantly enhanced (0.47 + or - 0.01% phosphate-buffered saline) and the deformability at shear stress of 3.9 Pa was not significantly reduced (0.36 + or - 0.01 elongation index [EI]). The deformability at 50 Pa was reduced (0.58 + or - 0.01-0.54 + or - 0.01 EI) but remained within reference values (0.53 + or - 0.04). During 5 weeks of storage, adenosine triphosphate was reduced by 54% whereas mean cell volume, pH, and mean cell hemoglobin concentration were minimally affected. RBC biochemical and physical alterations during storage minimally affected the RBC ability to aggregate and deform, even after prolonged storage. The rheologic properties of leukoreduced RBC units were well preserved during 7 weeks of routine blood bank storage.

English

Locally distilled liquor (Akpeteshie) is a beverage which is widely consumed in Ghana. It is produced from different raw materials. The purpose of this research was to determine the presence and levels of certain contaminants in akpeteshie from the various sources and to determine effects of ambient temperature, refrigeration, pasteurization and pasteurization in combination with low temperature for the liquor stored for seven weeks. The contaminant microorganisms are spore forming gram positive&nbsp;Bacillus&nbsp;spp., responsible for converting alcohol to acetic acid. Total viable count (TVC) reached 25, 120 cfu/100 ml during the first week of storage, under room temperature in the most contaminated sample and thereafter, increased till the end of the storage period. Storage under the other conditions drastically retarded microbial growth. pH decreased from 5.0 to 2.7 at the end of storage period while the titrable acidity increased from 1.10 to 1.63. However, the pH and titrable acidity varied at slower rates in samples stored under other conditions. An increase from 0.02 to 0.04 was recorded for the acetic acid content of S2 (sample obtained from the second production site in the district; New Town). The presence of acetic acid, iron and copper metals were detected in all the samples.&nbsp;The study therefore concludes that the various storage conditions had an appreciable effect on the quality of akpeteshie in the order;&nbsp;storage at room temperature followed by the refrigeration, pasteurization, then pasteurization in combination with refrigeration in increasing order of effect&nbsp;and that akpeteshie pasteurized and refrigerated is the best for consumption. &nbsp; Key words:&nbsp;Akpeteshie, ambient temperature, Ghana, refrigeration, pasteurization. &nbsp; &nbsp;

Effect of storage conditions on the shelf life of locally distilled liquor (Akpeteshie)

Locally distilled liquor (Akpeteshie) is a beverage which is widely consumed in Ghana. It is produced from different raw materials. The purpose of this research was to determine the presence and levels of certain contaminants in akpeteshie from the various sources and to determine effects of ambient temperature, refrigeration, pasteurization and pasteurization in combination with low temperature for the liquor stored for seven weeks. The contaminant microorganisms are spore forming gram positive Bacillus spp., responsible for converting alcohol to acetic acid. Total viable count (TVC) reached 25, 120 cfu/100 ml during the first week of storage, under room temperature in the most contaminated sample and thereafter, increased till the end of the storage period. Storage under the other conditions drastically retarded microbial growth. pH decreased from 5.0 to 2.7 at the end of storage period while the titrable acidity increased from 1.10 to 1.63. However, the pH and titrable acidity varied at slower rates in samples stored under other conditions. An increase from 0.02 to 0.04 was recorded for the acetic acid content of S2 (sample obtained from the second production site in the district; New Town). The presence of acetic acid, iron and copper metals were detected in all the samples. The study therefore concludes that the various storage conditions had an appreciable effect on the quality of akpeteshie in the order; storage at room temperature followed by the refrigeration, pasteurization, then pasteurization in combination with refrigeration in increasing order of effect and that akpeteshie pasteurized and refrigerated is the best for consumption.

Viability of Lactobacillus acidophilus in synbiotic guava mousses and its survival under in vitro simulated gastrointestinal conditions

The effects of refrigeration, freezing and substitution of milk fat by inulin and whey protein concentrate (WPC) on Lactobacillus acidophilus La-5 viability and resistance to gastric and enteric simulated conditions in synbiotic guava mousses effects were investigated. Refrigerated mousses supplemented with WPC presented the best probiotic viability, ranging from 7.77 to 6.24 log cfu/g during 28 days of storage. The highest probiotic populations, above 7.45 log cfu/g, were observed for all frozen mousses during 112 days of storage. Decreased L. acidophilus survival during the in vitro gastrointestinal simulation was observed both for refrigerated and frozen mousses. Nonetheless, for the refrigerated mousses, the addition of inulin enhanced the probiotic survival during the in vitro assays in the first week of storage. L. acidophilus survival in simulated gastrointestinal fluids was also improved through freezing. The frozen storage may be used to provide increased shelf-life for synbiotic guava mousses. Even though the protective effect of inulin and WPC on the probiotic microorganism tested was shown to be more specific for the refrigerated products, the partial replacement of milk fat by these ingredients may also help, as it improves the nutritional value of mousses in both storage conditions.

VIABILITAS PSEUDOMONAD Fluorescens ISOLAT Pf-122 DALAM BEBERAPA FORMULA

The objectives of this research were to examine effect of several formulas on the viability of Pseudomonas Fluorescens isolate Pf- 122. The eight formulations include carriers, additives, and concentration of Pf-122. The efficacy of various formulation in maintaining the population of Pf-122 in storage was assessed. The result of the viability test of Pf-122 in formula showed that the highest population of Pf-122 in week 0 was observed on the formula 1, viz the formula with combination of pupuk kandang as carrier and CMC as additive and Pf-122 at the concentration of 1010 CFU/ml. The bacterial population of the formula number1 could reach 4.8 × 1010 CFU/formula and followed by the formulas number 2,3,4,5,6, and 7. The lowest population was observed on the formula number 8 with the density of 5.8 × 106 CFU/formula. The bacterial population decreased during storage in all of the formulas and even it could not be detected in the formulas number 3 and 4 after the first week of storage. In the formulas number 1 and 2 survived within 3 months.

Post mortem changes produced in the muscle of sea bream ( Sparus aurata) during ice storage

The post mortem degradation processes that take places in fish muscle gradually modify the initial state of freshness. Tissue degradation is accompanied by drastic myofibrillar proteolysis produced as a consequence of the activation of proteolytic enzymes. In this study, structural changes were correlated with the textural properties of sea bream ( Sparus aurata) muscle during 14 days of post mortem cold storage through the immunohistochemical detection of muscle filament proteins (desmin, actin and dystrophin), as well as endoproteases (µ-calpain, m-calpain) and their endogenous inhibitor (calpastatin). Actin and desmin were detected in fish muscle as late as 10 days post mortem (dpm) while dystrophin could not be detected after 4 dpm. In contrast , labelling for both calpains and calpastatin persisted during the entire storage period. Fracturability was clearly reduced after 7 dpm, while greatest changes in hardness, gumminess and chewiness were observed during the first week of storage. Our immunohistochemical observations indicate the disappearance of cytoskeleton proteins at different times post mortem. Thus, actin and desmin persist even when the muscle tissue shows a deteriorated appearance and texture, while dystrophin vanishes soon after the death of the fish. Detachment between myofibres and the myocommata was concomitant with the loss of dystrophin and also corresponded to the time when the reduction in flesh hardness observed was most significant. On the contrary, after 4 days of storage, calpain activity remained practically unaltered in refrigerated muscle specimens.

Compositional Changes in Cassia mimosoides var. noname (M.) Essential Oil

The volatile flavor constituents of Cassia mimosoides var. noname (M.) essential oil were investigated by capillary GC and GC-MS. Compositional changes of the essential oil were analyzed after storage for 1, 2, 3, 4, 5, 6, 9, 12 and 15 weeks at 4 and 25°C. One hundred volatile flavor components were identified in the essential oil. n-Butylidene dihydrophthalide were the most abundant component. The contents of camphene, limonene, α-cedrene, longifolene, β-caryophyllene, γ-elemene and α-humullene increased in the initial stage of storage. A remarkable increase in the pentanal content was noticed in the essential oil stored at 25°C. A pronounced increase in the concentration of cineol, terpinen-4-ol, nerol, dehydrocarveol and thymol, and decrease in β-elemol, cedrol and β-eudesmol were observed during storage. Phthalides were predominant in Cassia mimosoides var. noname (M.) essential oil, and its content was nearly constant during storage at 4°C, however, it increased after first week of storage at 25°C.

Improving cranberry shelf-life using high voltage electric field treatment

Cranberries ( Vaccinium macrocarpon Aiton) were treated with high voltage electric fields (HVEF) of 2, 5 or 8 kV cm −1 in strength for 30, 60 or 120 min in a parallel plate electrode system. The treated berries were stored at ambient conditions (23 °C and 65% RH) for three weeks to study the effect of treatments on their respiration rate, physiological loss of mass (PLM), colour, total soluble solids (TSS) and skin puncture strength. Resulting respiration rates were in the range of 11.69–14.56 mL CO 2 kg −1 h −1 after the first week of storage, and increased to 13.95 and 21.33 mL CO 2 kg −1 h −1 by the end of third week. For both two and three weeks of storage, HVEF-treated cranberries showed significantly lower respiration rates than the control. This particular attribute indicates the potential of HVEF for improving shelf-life. The PLM of HVEF-treated cranberries were in the range of 23.2–30.4% after three weeks of storage. There was no significant difference between treated and untreated berries in terms of absolute L ∗, a ∗ and b ∗ colour values; however, the colour difference value Δ E ∗ab of treated berries was somewhat greater. The TSS content of various HVEF-treated cranberries was in the range of 7.27–7.69 °B, similar to the TSS content of untreated berries (7.4 °B) before storage. The skin puncture strength of different HVEF-treated cranberries was in the range of 11.7–14.3 N; while the untreated berries (11.2 N) showed lower values prior to storage.