Changes of DNA quality and meat physicochemical properties in bovine supraspinatus muscle during microwave heating

Effects of Cow's Milk Processing on MicroRNA Levels

MicroRNAs (miRNAs) regulate gene expression and might resist adverse physicochemical conditions, which makes them potential biomarkers. They are being investigated as biomarkers of dairy production systems, based on the variations in their levels in raw milk depending on animal diet and management. Whether miRNA levels can serve as biomarkers for dairy products remains unclear, since technological or culinary treatments, such as fermentation, may alter their levels. Here, 10 cow dairy farms were sampled in Asturias (north-west Spain) and milk samples were subjected to microwave heating or used to produce yogurt or cheese. Total RNA was isolated from raw milk and three derived products, and levels of seven miRNAs, selected based on previous studies as possible milk production system biomarkers, were assessed by RT-qPCR. The treatments decreased levels of all miRNAs to some extent. These results also imply that cheesemaking increases the concentration of miRNAs in this product; raw milk and cheese supposedly may provide similar concentrations of miRNAs, higher than those of yogurt and microwaved milk. They also indicate that the content of certain miRNAs in raw milk cannot necessarily be extrapolated to other dairy products.

Effects of different cooking methods on the proximate composition and physical properties of Brown shrimp (Metapenaeus dobsonii) during cooking and freezing cycle

Present study aimed to evaluate the changes in proximate composition and physical attributes in brown shrimp (Metapenaeus dobsonii) exposed to different methods of cooking followed by freezing. For this, three different grades (100/200, 200/300, and 300/500 numbers per kg) of brown shrimp were cooked at 90°C till the core temperature of the product reaches 85°C using hot water, steam, and microwave (400W) techniques. The changes in yield, cooking loss, proximate composition, textural, and colour profile were assessed for cooked shrimps. The cooking loss was higher for larger grades of shrimp, whereas shrimp cooked using hot water exhibited the highest cooking loss. Lowest cooking loss was observed for microwave-cooked shrimp. Moisture content decreased after cooking whereas protein, fat, ash, and calorie content increased. After cooking, different grades of shrimp showed an increase in their lightness (L*), redness (a*), and yellowness (b*) values. The smaller grade shrimp exhibited lower value for cohesiveness, hardness, chewiness, and gumminess. Different cooking techniques yielded cooked shrimp of varying hardness values.

Screening of P-35S, P-FMV, and T-NOS genetic elements in microwave-treated genetically modified cereal flours

BACKGROUND

Reliable and efficient methods for detecting genetically modified organisms (GMOs) in unprocessed and processed food will be essential for establishing an effective system for traceability all along the supply chain. It is important to understand the detection of GMOs following microwave treatment, which is a common processing method used in various food products such as flours. Therefore, this study aimed to detect the presence of Cauliflower mosaic virus (CaMV) 35S promoter (P-35S), Figwort mosaic virus (FMV) promoter (P-FMV), and T-NOS (nopaline synthase terminator) genetic elements in DNA samples from untreated and microwave-treated genetically modified (GM) cereal flour samples using the qualitative polymerase chain reaction (PCR) based screening method.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [Begüm Zeynep] Last name [Hançerlioğulları]. Also, kindly confirm the details in the metadata are correct. The author names were presented accurately and in the correct sequence (given name, middle name/initial, family name).  Author 1 Given name: [Begüm Zeynep] Last name [Hançerlioğulları]. Author 2 Given name: [Remziye] Last name [Yılmaz]. The details in the metadata are correct.

METHODS AND RESULTS

DNA was extracted from all samples, and the efficiency of the qualitative PCR screening technique was tested by the verification studies. We performed an inhibition study with plant-specific actin (ACT) gene to the effectiveness of confirming the DNA extraction method. Then, we made the confirming of the qualitative PCR system by method performance testing criteria. The high quality and quantity of the DNA extracts from untreated and microwave-treated flour samples indicated the applicability of qualitative PCR screening assays. The results showed that microwave radiation does not significantly impact the genetic element screening in flour materials.

CONCLUSION

Untreated and microwave-treated flour samples had amplifiable DNA for the simultaneous screening of three genetic elements. The qualitative screening tests conducted in this study produced dependable outcomes, thus, can be successfully used for monitoring in control laboratories.

Dietary exposure assessment of infant formula and baby foods' oxidized lipids in the US population

Baby Foods (BFs) and Infant formulas (IFs) are the main sources of nutrition for an infant throughout the 1st year of life. Various enriched products are commercially available for parents seeking to fulfill their baby's nutritional needs. Consequently, different bioactive lipids are present in BFs and IFs, including dietary oxysterols (DOxS), whose known toxicity has been associated with mutagenicity, cancer, and other chronic diseases. In this work, we performed an exposure assessment of 25 bioactive lipids on IFs (n = 30) and BFs (n = 13) commercially available in the US. To determine dietary exposure, we used EPA's SHEDS-HT probabilistic model. Even though β-Sitosterol was the most exposed bioactive lipid with 75,410 μg/day, cholesterol was the most absorbed compound during the entire first year (19.3 mg/day). Additionally, we found 7α-hydroxycholesterol (7α-OH) as a potential DOxS biomarker of the BFs manufacturing process. This is the first time an infant's exposure assessment (including DOxS) after BFs and IFs consumption is performed, enabling much-needed information regarding these hazardous compounds and their potential effects on infants' health.

Dynamic alterations in protein, sensory, chemical, and oxidative properties occurring in meat during thermal and non-thermal processing techniques: A comprehensive review

Meat processing represents an inevitable part of meat and meat products preparation for human consumption. Both thermal and non-thermal processing techniques, both commercial and domestic, are able to induce chemical and muscle's proteins modification which can have implication on oxidative and sensory meat characteristics. Consumers' necessity for minimally processed foods has paved a successful way to unprecedented exploration into various novel non-thermal food processing techniques. Processing of meat can have serious implications on its nutritional profile and digestibility of meat proteins in the digestive system. A plethora of food processing techniques can potentially induce alterations in the protein structure, palatability, bioavailability and digestibility via various phenomena predominantly denaturation and Maillard reaction. Apart from these, sensory attributes such as color, crispness, hardness, and total acceptance get adversely affected during various thermal treatments in meat. A major incentive in the adoption of non-thermal food processing is its energy efficiency. Considering this, several non-thermal processing techniques have been developed for evading the effects of conventional thermal treatments on food materials with respect to Maillard reactions, color changes, and off-flavor development. Few significant non-thermal processing techniques, such as microwave heating, comminution, and enzyme addition can positively affect protein digestibility as well as enhance the value of the final product. Furthermore, ultrasound, irradiation, high-pressure processing, and pulsed electric fields are other pivotal non-thermal food processing technologies in meat and meat-related products. The present review examines how different thermal and non-thermal processing techniques, such as sous-vide, microwave, stewing, roasting, boiling, frying, grilling, and steam cooking, affect meat proteins, chemical composition, oxidation, and sensory profile.

Impact of different microwave treatments on food texture

Electromagnetic waves are frequently used for food processing with commercial or domestic type microwave ovens at present. Microwaves cause molecular movement by the migration of ionic particles or rotation of dipolar particles. Considering the potential applications of microwave technique in food industry, it is seen that microwaves have many advantages such as saving time, better final product quality (more taste, color, and nutritional value), and rapid heat generation. Although microwave treatment used for food processing with developing technologies have a positive effect in terms of time, energy, or nutrient value, it is also very important to what extent they affect the textural properties of the food that they apply to. For this purpose, in this study, it has been investigated that the effects of commonly used microwave treatments such as drying, heating, baking, cooking, thawing, toasting, blanching, frying, and sterilization on the textural properties of food. In addition, this study has also covered the challenges of microwave treatments and future work. In conclusion, microwave treatments cause energy saving due to a short processing time. Therefore, it can be said that it affects the textural properties positively. However, it is important that the microwave processing conditions used are chosen appropriately for each food material.

A Practical Approach to Identifying Processed White Meat of Guinea Fowl, Rabbit, and Selected Fish Species Using End-Point PCR

Among the foodstuff, most often adulterated are white meat and meat products as well as fish and fish products. For this reason, we evaluated in practice the possibilities of identifying selected species of white meat, i.e., guinea fowl and rabbit as well as four fish species, namely, pollock, hake, sole, and panga, in thermally treated samples. The aim was to check whether the previously published in the scientific literature species-specific primers allows for the identification of processed meat using the end-point PCR technique. To identify the six species, the short sequence fragments (from 130 to 255 bp) of 12S rRNA, COX3, mitochondrial ATP synthase Fo subunit 6 (ATP6) gene, pantophysin (Pan I) gene, 5S rRNA gene, and microsatellite markers (locus: Phy01-KUL) were selected. Stability and specificity of the six pair primers were evaluated on cooked and autoclaved meat, and commercially processed food samples such as rabbit and guinea pâtés, ready-made baby food, and breaded, fried, and deep-frozen fish products. The method proved to be useful for the authentication of severely processed food products against fraudulent species substitution and mislabelling and this approach may be an alternative to more advanced and more expensive PCR techniques.

Effect of secondary heat-induced aggregation on pork meat batter protein conformation, hydration characteristics, textural quality and in vitro digestibility

SH has caused fierce aggregation and the conformation transition from α-helix to β-sheets, which resulted in the decrease of WHC, textural quality and in vitro digestibility.

Qualitative and quantitative assessment of DNA quality of frozen beef based on DNA yield, gel electrophoresis and PCR amplification and their correlations to beef quality

Freezing is a practical method for meat preservation but the quality of frozen meat can deteriorate with storage time. This research investigated the effect of frozen storage time (up to 66 months) on changes in DNA yield, purity and integrity in beef, and further analyzed the correlation between beef quality (moisture content, protein content, TVB-N value and pH value) and DNA quality in an attempt to establish a reliable, high-throughput method for meat quality control. Results showed that frozen storage time influenced the yield and integrity of DNA significantly (p < 0.05). The DNA yield decreased as frozen storage time increased due to DNA degradation. The half-life (t_1/2 = ln2/0.015) was calculated as 46 months. The DNA quality degraded dramatically with the increased storage time based on gel electrophoresis results. Polymerase chain reaction (PCR) products from both mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) were observed in all frozen beef samples. Using real-time PCR for quantitative assessment of DNA and meat quality revealed that correlations could be established successfully with mathematical models to evaluate frozen beef quality.

Authentication of processed meat products by peptidomic analysis using rapid ambient mass spectrometry

We present the application of a novel ambient LESA-MS method for the authentication of processed meat products. A set of 25 species and protein-specific heat stable peptide markers has been detected in processed samples manufactured from beef, pork, horse, chicken and turkey meat. We demonstrate that several peptides derived from myofibrillar and sarcoplasmic proteins are sufficiently resistant to processing to serve as specific markers of processed products. The LESA-MS technique required minimal sample preparation without fractionation and enabled the unambiguous and simultaneous identification of skeletal muscle proteins and peptides as well as other components of animal origin, including the milk protein such as casein alpha-S1, in whole meat product digests. We have identified, for the first time, six fast type II and five slow/cardiac type I MHC peptide markers in various processed meat products. The study demonstrates that complex mixtures of processed proteins/peptides can be examined effectively using this approach.

Meat authentication: a new HPLC-MS/MS based method for the fast and sensitive detection of horse and pork in highly processed food

Fraudulent blending of food products with meat from undeclared species is a problem on a global scale, as exemplified by the European horse meat scandal in 2013. Routinely used methods such as ELISA and PCR can suffer from limited sensitivity or specificity when processed food samples are analyzed. In this study, we have developed an optimized method for the detection of horse and pork in different processed food matrices using MRM and MRM(3) detection of species-specific tryptic marker peptides. Identified marker peptides were sufficiently stable to resist thermal processing of different meat products and thus allow the sensitive and specific detection of pork or horse in processed food down to 0.24% in a beef matrix system. In addition, we were able to establish a rapid 2-min extraction protocol for the efficient protein extraction from processed food using high molar urea and thiourea buffers. Together, we present here the specific and sensitive detection of horse and pork meat in different processed food matrices using MRM-based detection of marker peptides. Notably, prefractionation of proteins using 2D-PAGE or off-gel fractionation is not necessary. The presented method is therefore easily applicable in analytical routine laboratories without dedicated proteomics background.

Advanced retorting, microwave assisted thermal sterilization (MATS), and pressure assisted thermal sterilization (PATS) to process meat products

Conventional thermal processes have been very reliable in offering safe sterilized meat products, but some of those products are of questionable overall quality. Flavor, aroma, and texture, among other attributes, are significantly affected during such processes. To improve those quality attributes, alternative approaches to sterilizing meat and meat products have been explored in the last few years. Most of the new strategies for sterilizing meat products rely on using thermal approaches, but in a more efficient way than in conventional methods. Some of these emerging technologies have proven to be reliable and have been formally approved by regulatory agencies such as the FDA. Additional work needs to be done in order for these technologies to be fully adopted by the food industry and to optimize their use. Some of these emerging technologies for sterilizing meat include pressure assisted thermal sterilization (PATS), microwaves, and advanced retorting. This review deals with fundamental and applied aspects of these new and very promising approaches to sterilization of meat products.