Frozen Storage Research Articles

A functional mutation in the AMPD1 promoter region affects promoter activity and breast meat freshness in chicken.

Freshness is an important index to determine the quality deterioration (protein degradation and changes in appearance) of chilled chicken meat and is a primary consideration of consumers. Adenosine monophosphate deaminase 1 (AMPD1) catalyzes the deamination of adenosine monophosphate to inosine monophosphate in skeletal muscle and is the rate-limiting step in the purine nucleotide cycle. Inosine monophosphate is regarded as an important indicator of meat freshness in chicken. This study investigated the association of polymorphisms in the chicken AMPD1 promoter region with meat freshness during freezing storage. An SNP (c. -905G>A) was found to be associated with the freshness (K-value) of chicken breast meat. Chickens with the AA genotype had significantly lower K-values than those with GG and AG genotypes (P<0.01). Individuals with the AA genotype also had higher breast meat AMPD1 mRNA levels than did those with the GG and AG genotypes (P<0.01, P<0.05). A luciferase assay revealed that genotype AA had greater transcriptional activity than genotype GG. Transcription factor binding site analysis identified distinct putative transcription factor binding sites in the two alleles of mutation site c. -905. In summary, we identified an SNP (c. -905G>A) in the promoter region of the AMPD1 gene that may modulate the binding affinity of different transcription factors to control AMPD1 expression and affect the freshness K-value of chicken meat.

The Science is There: Key Considerations for Stabilizing Viral Vector-Based Covid-19 Vaccines.

Once Covid-19 vaccines become available, 5–10 billion vaccine doses should be globally distributed, stored and administered. In this commentary, we discuss how this enormous challenge could be addressed for viral vector-based Covid-19 vaccines by learning from the wealth of formulation development experience gained over the years on stability issues related to live attenuated virus vaccines and viral vector vaccines for other diseases. This experience has led –over time– to major improvements on storage temperature, shelf-life and in-use stability requirements. First, we will cover work on ‘classical’ live attenuated virus vaccines as well as replication competent viral vector vaccines. Subsequently, we address replication deficient viral vector vaccines. Freeze drying and storage at 2–8 °C with a shelf life of years has become the norm. In the case of pandemics with incredibly high and urgent product demands, however, the desire for rapid and convenient distribution chains combined with short end-user storage times require that liquid formulations with shelf lives of months stored at 2–8 °C be considered. In confronting this “perfect storm” of Covid-19 vaccine stability challenges, understanding the many lessons learned from decades of development and manufacturing of live virus-based vaccines is the shortest path for finding promising and rapid solutions.

The effect of herbal salt as a natural antioxidant in preserving fish during freezing storage

Abstract The changes in chemical composition, chlorides, phenols and fatty acid profile of roasted or not Dolphinfish (Coryphaena hippurus Linnaeus, 1758) samples, after using or herbal salt or common iodized salt (NaCl), during storage under freezing, were evaluated. The ash and chloride contents were significantly higher (p 0.05), when compared to the roasted and pre-treated with herbal salt. However, statistically lower values were detected (p > 0.05) in roasted samples pre-treated with salt, showing a positive correlation between phenolic compounds and the antioxidant activity exerted by herbs, in relation to the profile of fatty acids during storage under freezing, preserving nutritional quality. These results contributed to show the good functionality of herbal salt, in addition to encouraging healthy eating habits, by reducing common salt consumption.

Preservation Technique of Filamentous Fungi Based on Inactive Metabolism at Indonesian Culture Collection (InaCC)

Preservation is the act of preserving to keep, maintain, and conserve microbial strains to ensure their optimal viability and genetic stability. A wide variety of preservation techniques are available for preserving filamentous fungi. Most of the metabolically inactive preservation, such as freezing, cryopreservation, lyophilization, or L-drying, is widely accepted for long-term preservation of filamentous fungi with minimum viability loss and genetic changes. This study determined the viability and effectiveness of freezing or cryopreservation method in a fungal assemblage from the Indonesian Culture Collection (InaCC). The viability and growth rate of 40 fungal strains from InaCC were tested after three years of storage in the electric deep freezer (-80°C with 10% glycerol and 5% trehalose as cryoprotectant). The results showed that 95% of the observed strains could maintain their viability and growth rate after cryopreserved and storage for more than three years at -80°C. However, 5% of them showed a low growth rate and loss of viability. It was concluded that the cryopreservation technique by freezing at -80°C is suitable to maintain the viability of filamentous fungal cultures.

Olive Leaf Water Extract Protects Chicken Breast Sausages Against Quality Deterioration Induced by Frozen Storage.

This study aimed to determine the effect of olive leaf water extract (OEx) on the physical properties of chicken breast sausage (CBS) and the preventive effect of OEx against lipid oxidation in CBS during frozen storage. CBSs, to which 0.1 and 0.5% (w/w) OEx were added to minced meat, were stored frozen at −20°C for 60 days. The thawing weight loss of control CBS without OEx increased with the frozen storage period, while OEx-CBSs did not change, from 15 to 60 days in storage. The water-holding capacity, breaking strength, elasticity, and viscosity of control CBS decreased upon frozen storage, while those of OEx-CBSs did not change. The observation of CBSs using scanning electron microscopy showed that OEx-CBSs that were stored frozen, unlike control CBS, maintained a structure similar to their unfrozen counterparts. These results indicate that OEx confers resistance to CBS upon freezing. Furthermore, the application of OEx to CBS suppressed lipid oxidation, decrease in pH and discoloration induced by frozen storage. Thus, this natural OEx is useful in improving the physical and chemical qualities of frozen processed poultry foods.

Onboard Evaluation of Variable Water Flow and Recirculation Effects on Bleeding of Atlantic Cod (Gadus morhua).

The aim of the study was to explore the effects of different design variables in the onboard bleeding process of cod on bleeding efficiency and the resulting product quality. A time- and flow-controlled process was used to create variable bleeding conditions for whole gutted cod onboard a wet-fish trawler. Two main design variables influencing the bleeding process are the pump flow recirculation (PFR) and the water replacement ratio (WRR); they were studied in five different combinations (groups). The effects of different bleeding conditions were evaluated by measurements of free fatty acids (FFAs), phospholipids (PLs), and total heme iron (HI) content during freezer storage for up to four months. The results for PL content and the regression model indicate that the enzyme activity in the fish muscle is lower in cases where PFR exerts greater influence in the bleeding process than WRR. The effects of successful blood removal also seem to be most noticeable after one month of freezer storage, rather than in fresh cod after seven days or after four months of simulated frozen food-chain storage. The study indicates that, with the bleeding medium to fish ratio of around 3:1 and enough WRR (over 100% replacement in 20 min), the PFR becomes the limiting design parameter regarding efficient blood removal and should be at least 10% of the tank volume per minute to ensure enough recirculation and flow of water in the bleed-out tanks.

Freezing of pomegranate seeds coated with chitosan and evaluating its quality during freezing storage

Freezing of pomegranate seeds coated with chitosan and evaluating its quality during freezing storage

Effect of Freezing Time on Tissue Factor Activity and Macronutrients of Human Milk.

Human milk proteins are known as vital molecules for infant development and growth. Tissue factor is one of these human milk proteins that its role in human milk has not been cleared yet. Therefore, the first aim of this study was to detect the tissue factor activity of human milk and also was to investigate the effect of extended freezer storage on the milk tissue factor activity. The relationship between the tissue factor activity and macronutrient content and pH of milk was also investigated in this study. Under this aim, mature human milk samples were obtained from 8 healthy women. Collected human milk samples were pooled and divided into aliquots that were stored at -20°C until the day to be analyzed. Milk tissue factor activity, protein, fat, lactose, energy, water, density, and pH levels were determined for up to six months. By two months from the freezing, tissue factor activity did not significantly change but significantly decreased at the end of the six months. From the first month to six months from freezing, lactose, protein, fat, and energy levels showed a significant decline. Milk pH did not change with freezing at the end of 6months. In conclusion, TF activity maintained its first-day activity until the second month after being pumped. The increased interest in breast milk leads us to believe that the gap existing in the knowledge of breast milk bioactive components like TF will be complemented with new research data.

Influence of Frozen Storage on Properties of Rohu and Pangas Protein Isolates Obtained from Its Processing Waste

ABSTRACT The aim of this investigation was to study the influence of freezing and frozen storage on properties of protein isolates obtained from rohu and pangas processing waste through pH shift processing (pH 2.0 and 13.0). Quality changes were measured for a period of 3 months at −18°C. Increase in storage period decreased the myoglobin content, pigment content, and cooking yield (p < .05). Increase in frozen storage period increased thiobarbituric reactive substances to a range of 4.09–4.98 mg MAD kg−1. L* values of isolates decreased with the advancement of storage time (p < .05). Quality of protein gels was also affected by freezing and frozen storage. At the end of the storage period, pangas acid, pangas alkali, rohu acid, and rohu alkali isolate gels had folding test scores of 2.0, 1.0, 1.0, and 1.0, respectively. Gel strength values also decreased significantly from 1131.36, 1001.80, 847.57, and 746.88 g cm to 325.63, 226.77, 224.98, and 203.95 g cm for pangas acid, pangas alkali, rohu acid, and rohu alkali isolates, respectively. The effect of frozen storage was found to be high on pangas alkali isolate, which was evident by the drastic fall of G’ and G” values (p < .05).

Comparative study of the impacts of conventional freezing and dehydrofreezing on apple fruit quality during storage

The present study deals with the impact of storage time on the quality of dehydrofrozen versus conventionally frozen apple. Samples were submitted to freezing as fresh fruit or following the first stage of air drying. The quality was evaluated along a freezing storage period of 18 months under -18 °C. Thaw exudate water (TEW), total colour difference (TCD), and total polyphenol content (TPC) of dehydrofrozen/thawed samples were assessed regarding the water content (W) versus the frozen storage time (FST) (0-18 months). Dehydrofreezing exhibited significant effects on TEW and TCD of dehydrofrozen/thawed apples. Indeed, the lower the W, the lower the TEW content and TCD of partially dried frozen/thawed samples. TPC losses were significant for samples without any pre-dehydration stage and decreased when initial water content decreased. The 18-month frozen storage at -18 °C had the most insignificant effects on all quality response variables for the previously most dried samples. Thus, adequate drying of fruit before freezing is a relevant way to maintain the stability of fruit quality during long-term storage.

Impact of Media Heat Treatment on Cell Morphology and Stability of L. acidophilus, L. johnsonii and L. delbrueckii subsp. delbrueckii during Fermentation and Processing

Manufacturers of starter cultures and probiotics aim to provide preparations with the highest possible amount of living cells and assurance of long-term storage stability. Thereby the industrial economy and thus an efficient outcome of the processes is of utmost importance. Earlier research has shown that the sterilization procedure of the microbial culture medium tremendously impacts growth performance of heating product-sensitive Lactobacillus strains. Thus, three different strains, i.e., L. acidophilus NCFM, L. johnsonii La-2801 and L. delbrueckii subsp. delbrueckii La-0704, were investigated for the influence of media heat pretreatment on cell morphology and stability during fermentation and further freeze drying and storage. The data indicate a relationship between the heating time of the culture medium, which is associated with an increase in browning reactions, and the cultural characteristics of the three strains. The resulting characteristic cell sizes of the cultures could be a major reason for the different stability properties during processing and storage that were observed. Besides the obvious relevance of the results for the production of starter cultures and probiotics, the pleomorphic phenomenon described here could also be a subject for other biotechnological processes, where heat-mediated media conversions, and thereby related cellular effects, could be a topic. Future studies have to show if further functional properties are influenced by the cell morphology and which cellular mechanisms lead to the observed pleomorphism.

EFFECT OF FREEZING ON THE MILK QUALITY OF COWS

Due to the fact that milk has a short shelf life, the issue of its freezing and long-term storage in the frozen state is relevant. A study was conducted on the effect of freezing on the milk quality after its defrosting of cows-mothers and cows-daughters of Red-Motley breed. As a result, it was established how milk quality indicators to change after five months of storage in a frozen state in cows of two age groups. A high correlation was established between quality indicators before and after freezing. The influence of the “freezing” factor on milk quality indicators was recognized statistically significant, the “generation” factor – not significant.

Changes in myoglobin content in pork Longissimus thoracis muscle during freezing storage

In this study, pork Longissimus thoracis muscle was used, which was frozen in a chamber and thawed under controlled conditions. The color profile and the surface myoglobin were evaluated. A thermal analysis was performed by modulated differential scanning calorimetry (MDSC), and Fourier-transform infrared spectroscopy with attenuated total reflection (FTIR-ATR). It was found that there were important effects in myoglobin due to the freeze-thawing process in parameters such as pH, luminosity (L*), and chroma values, as well as in activation energies (Ea) and denaturation enthalpy (ΔH) between myoglobin forms. In raw meat, it was found that there was a greater proportion of deoxymyoglobin, and in frozen-thawed samples, metmyoglobin was the most abundant form, indicating that are significant effects which are correlated with the changes in tri-stimulus coordinates and with the thermal and chemical parameters in pork meat.

Bacterial stability with freezer storage of human milk.

Human milk supports the development of a beneficial newborn intestinal microflora. We have shown previously that human milk had reduced bacteria but unchanged nutrient composition when stored at-20°C for up to nine months. We suspected declining bacterial colony counts were manifestations of bacterial dormancy and not failure of survival. We investigated differences in selected bacterial colony counts (lactobacillus, bifidobacteria, staphylococcus, streptococcus and enterococcus) in human milk stored for 2 and 12weeks at-20°C in either manual or automatic defrost freezers and whether reduced bacterial counts at 12weeks were the result of dormancy or failure of survival. Freshly expressed milk was obtained from mothers in the NICU, divided into aliquots and stored for 2 and 12weeks at-20°C in either automatic or manual defrost freezers. Subsequently, duplicate aliquots, one thawed and the other thawed and maintained at room temperature for 4h, were plated to assess bacterial colony counts. Significant declines in bacterial colony counts were seen from 2 to 12weeks freezer storage for all bacteria. There were no differences in colony counts between freezer types. Once thawed, no further bacterial growth occurred. Short-term freezer storage for 12weeks resulted bacterial killing. Type of freezer used for storage did not have an impact on bacterial survival. It is unknown whether the paucity of important probiotic bacteria in stored human milk has adverse effects on infants.

Characteristics of Mackerel Tuna (Euthynnus affinis) Fish Oil During Storage in Freezer

Red flesh fish contain in some varieties of fatty acids. One of the fish that has potential as a source of fish oil is mackerel tuna. The Fatty acid content in mackerel tuna can be used as the source of fatty acid for the human body if that component has been separated from other substances such as water or extracted from fish flesh. The method used to produce oil or fat from the materials suspected to have them is called extraction. While the way of extraction used is wet rendering. This research aims to know the characteristics of omega-3 during storage in the freezer. The Materials used in this research was Mackerel Tuna (Euthynnus affinis). This research was an experimental laboratory with three repetitions. The storage duration consisted of the zero and the thirtieth day. The parameters observed were the amount of yield, a profile of fatty acids, peroxide value, and the test of organoleptic during storage. Analysis data used variety analysis (ANOVA) and advanced test of Tukey HSD. The result data of the organoleptic test was analyzed by Kruskal Wallis test. The result showed that the yield of mackerel fish oil with wet rendering was 0,90% (w/w). There was nine profile of fatty acids consisting of SFA, MUFA, and PUFA. The omega-3 of mackerel tuna fish oil decreases during storage by 5,035% to 3,332%. The peroxide value has been increased from 13,59 meq/kg to 15,45 meq/kg. Organoleptic tests during storage decreased from 5,43 to 5,37. Storage of mackerel tuna fish oil significantly affected the content of fatty acids, peroxide value, and organoleptic value (P&lt;0,05)

PREVALENCE OF HUMAN PAPILOMAVIRUS IN SALIVA OF PATIENTS WITH HIV

Objective: To identify the presence of high-risk serotypes (subtypes 16 and 18) of human papillomavirus (HPV) in the saliva of patients with human immunodeficiency virus (HIV). Study Design: Observational cross-sectional study with a sample of 90 patients of both genders, between June and December 2014. An interview was conducted to identify the sociodemographic profile of the sample. A saliva collection was performed employing falcon tubes and solution for mouthwash with 5% sucrose, with subsequent freezer storage at –20°C. The identification of HPV virus and genotyping for serotype 16 and 18 was by standard polymerase chain reaction (PCR). Results: The predominant sample was male (65.6%), with a mean age of 38.8 years, ranging from 18 to 69 years, and a mean family income of 1.95 minimum wages (SD = 1.37). Specifically on the detection of HPV, 23 of 90 (25.6%) of the sample population evidenced the presence of the infection in the individuals surveyed. Serotypes 16 and 18 were present in 8 of 90 (8.9%) of the entire sample and 8 of 23 (4.7%) if only HPV-infected. Conclusion: HPV coinfection is commonly observed in patients with HIV.

Effect of ice maturation, freezing and heat treatment on the peelability and quality of cold water shrimps (Pandalus borealis)

Steamed (90 s) cold water shrimps (Pandalus borealis) were analysed for the effect of ice maturation (1–4 days) before steaming, frozen storage (2 months at −20 °C) and catching locations (2 batches) with respect to changes in texture, colour and peelability. In addition, the interdependency of the attributes of uncooked and steamed shrimps were assessed by analysing 1760 shrimps in total. Results showed that the longer maturation time the springier and more yellow the ready-to-eat shrimps got. Besides, frozen storage prior to ice maturation and steaming led to springier, chewier and harder shrimps compared to the unfrozen product. Frozen storage also induced increased yellowness, which negatively affected the quality of the shrimps. The expected positive effect of maturation time on peelability could not be confirmed by the mechanical peeling work measurements. Studying the interdependency of steamed and uncooked shrimps showed that the steaming process increased the springiness and decreased the hardness, resilience and chewiness of the shrimps as maturation took place. Furthermore, the steaming resulted in more white shrimps, which were slightly easier to peel. In conclusion, maturation time, freezing and steaming all affected the quality of the ready-to-eat shrimps, whereas the peeling work was not affected.

The influence of endogenous cathepsin in different subcellular fractions on the quality deterioration of Northern pike (Esox lucius) fillets during refrigeration and partial freezing storage.

The purpose of this study was to investigate the endogenous cathepsin activity in each subcellular fraction and the effect of this activity on myofibrillar protein and texture during refrigeration and partial freezing storage of northern pike (Esox lucius) fillets. The results showed that fillets stored under the refrigerated condition were more susceptible to oxidation than partial freezing. Endogenous cathepsin activity indicated that partial freezing destroys the integrity of lysosomes more effectively than refrigeration and inhibits the increase in cathepsin B and B + L in lysosomes. The activity of cathepsin B and B + L in lysosomes, mitochondria and myofibrils under the partial freezing conditions was always lower than that under refrigeration. Texture analysis showed that refrigeration had a negative impact on hardness and springiness. In conclusion, the cathepsin activity in each subcellular fraction was effectively inhibited and better textural characteristics were obtained with partial freezing than refrigeration.

The unique role of seed banking and cryobiotechnologies in plant conservation

Societal Impact StatementEroding plant diversity has serious implications for the well‐being of humanity and our planet. Conserving plants ex situ requires technologies that are rapidly advancing and readily accessible. The alarming loss of plant habitats has spawned global investment in technologies that focus on either conventional freezer storage, which exploit seed adaptations to survive drying, or on cryogenic platforms, that ensure long‐term survival of germplasm that is not amenable to conventional methods. Increasing evidence that germplasm survives for decades provide proof of concept, but also warns of the limited utility of stored germplasm that is not returned to the Earth.SummaryA future sustainable world requires concerted efforts to conserve plant biodiversity. Using an integrated approach, botanic gardens, arboreta, universities, governmental agencies, and non‐governmental organizations are addressing that challenge. Here, we summarize some of the technological advances, in an ever‐growing toolbox, that increase the scope of taxa that are conserved ex situ as well as the lifespans of diverse plant tissues that can be used as germplasm. Seed banking continues to be a powerful and efficient tool. Seeds that tolerate extreme drying and low temperature will likely survive at least 100 years using conventional conditions of a common freezer. The extreme tolerance of seeds among diverse taxa has led to the global growth of seed banks to over 1,750 currently, and the conservation of over 50,000 species. Not all plants produce seeds or seeds that survive freezer conditions. Predictive models provide insight into the extent of taxa needing alternative strategies and an initial list of such species is available. These “exceptional” species require cryobiotechnologies (cryogenic storage in liquid nitrogen and in vitro technologies), which provide effective, long‐term ex situ conservation for a wide variety of tissues beyond seeds. The application of cryobiotechnologies increases the potential for conserving all plant biodiversity. Restoration of plant biodiversity into the future will require institutional collaborations among living collections, seed banks, and cryobanks to ensure technology transfer, information gathering and sharing, and capacity building in centers of biodiversity.

Osmodehydrofreezing: An Integrated Process for Food Preservation during Frozen Storage.

Osmodehydrofreezing (ODF), a combined preservation process where osmotic dehydration is applied prior to freezing, achieves several advantages, especially in plant tissues, sensitive to freezing. OD pre-treatment can lead to the selective impregnation of solutes with special characteristics that reduce the freezing time and improve the quality and stability of frozen foods. ODF research has extensively focused on the effect of the osmotic process conditions (e.g., temperature, duration/composition/concentration of the hypertonic solution) on the properties of the osmodehydrofrozen tissue. A number of complimentary treatments (e.g., vacuum/pulsed vacuum, pulsed electric fields, high pressure, ultrasound) that accelerate mass transfer phenomena have been also investigated. Less research has been reported with regards the benefits of ODF during the subsequent storage of products, in comparison with their conventionally frozen counterparts. It is important to critically review, via a holistic approach, all parameters involved during the first (osmotic dehydration), second (freezing process), and third stage (storage at subfreezing temperatures) when assessing the advantages of the ODF integrated process. Mathematical modeling of the improved food quality and stability of ODF products during storage in the cold chain, as a function of the main process variables, is presented as a quantitative tool for optimal ODF process design.