Nitrates and nitrites have been traditionally used as curing agents in the production of cured meat products. Beneficial effects of the addition of nitrates and nitrites to meat products are the improvement of quality characteristics as well as the microbiological safety. The nitrates and nitrites are mainly responsible for the development of the distinct flavor, the stability of the red color, as well as the protection against lipid oxidation in cured meat products. The nitrites show important bacteriostatic and bacteriocidal activity against several spoilage bacteria as well as foodborne pathogens found in meat products. The nitrites prevent the growth and toxin production by Clostridium botulinum. According to Commission Regulation (EU) No. 1129/2011, nitrates (sodium nitrate, E251; potassium nitrate, E252) and nitrites (potassium nitrite, E249; sodium nitrite, E250) are listed as permitted food additives. Nitrates are relatively non-toxic, but nitrites, and nitrites metabolic compounds such as nitric oxide and N-nitroso compounds, have raised concern over potential adverse health effects. Recently, the International Agency for Research on Cancer (IARC) concluded that ingested nitrates or nitrites are probable carcinogen to humans under conditions favoring the endogenous nitrosation. Legal limits for the addition of nitrates and nitrites have been set by several countries and EU [Commission Regulation (EU) No. 601/2014]. Several data from recent reviews conducted in several countries on the levels of nitrates and nitrites in cured meat products were summarized. In recent reviews, the residual levels of nitrites in cured meat samples have been constantly reduced and are in accordance with the legal limits set by most countries.

In recent years, several foodborne viruses’ outbreaks have been recorded worldwide. Μost of the foodborne viruses have a low infection dose, are stable and can persist and survive in foods for a long time without loss of infectivity. The most important foodborne viruses are: human norovirus (HuNoV), human rotavirus (HRV), hepatitis A virus (HAV), hepatitis E virus (HEV), human astrovirus (HAstV), Aichi virus (AiV), sapovirus (SaV), human adenovirus (HAdV) and enterovirus (EV). In recent years, innovative non-thermal food-processing technologies including high-pressure processing (HPP), cold plasma (CP), ultraviolet light (UV), irradiation and pulsed electric field (PEF) for improving the quality and safety of foods, including foods of animal origin, have been under research. This review presents the recent data on foodborne viruses and reviews the innovative non-thermal technologies for the control of the foodborne viruses in foods.

Ochratoxin A (OTA) is a mycotoxin that is produced after the growth of several Aspergillus and Penicillium spp. in feeds or foods. OTA has been proved to possess nephrotoxic, hepatotoxic, teratogenic, neurotoxic, genotoxic, carcinogenic and immunotoxic effects in animals and humans. OTA has been classified as possibly carcinogenic to humans (Group 2B) by the IARC in 2016. OTA can be mainly found in animals as a result of indirect transmission from naturally contaminated feed. OTA found in feed can also contaminate pigs and produced pork products. Additionally, the presence of OTA in pork meat products could be derived from the direct growth of OTA-producing fungi or the addition of contaminated materials such as contaminated spices. Studies accomplished in various countries have revealed that pork meat and pork meat products are important sources of chronic dietary exposure to OTA in humans. Various levels of OTA have been found in pork meat from slaughtered pigs in many countries, while OTA levels were particularly high in the blood serum and kidneys of pigs. Pork products made from pig blood or organs such as the kidney or liver have been often found to becontaminated with OTA. The European Union (EU) has established maximum levels (ML) for OTA in a variety of foods since 2006, but not for meat or pork products. However, the establishement of an ML for OTA in pork meat and meat by-products is necessary to protect human health.

High-pressure processing (HPP) is an innovative non-thermal food preservation method. HPP can inactivate microorganisms, including viruses, with minimal influence on the physicochemical and sensory properties of foods. The most significant foodborne viruses are human norovirus (HuNoV), hepatitis A virus (HAV), human rotavirus (HRV), hepatitis E virus (HEV), human astrovirus (HAstV), human adenovirus (HuAdV), Aichi virus (AiV), sapovirus (SaV), and enterovirus (EV), which have also been implicated in foodborne outbreaks in various countries. The HPP inactivation of foodborne viruses in foods depends on high-pressure processing parameters (pressure, temperature, and duration time) or non-processing parameters such as virus type, food matrix, water activity (a_w), and the pH of foods. HPP was found to be effective for the inactivation of foodborne viruses such as HuNoV, HAV, HAstV, and HuAdV in foods. HPP treatments have been found to be effective at eliminating foodborne viruses in high-risk foods such as shellfish and vegetables. The present work reviews the published data on the effect of HPP processing on foodborne viruses in laboratory media and foods.

The microbiological quality of pasteurized milk samples (n = 39) collected during 13 weekly intervals from three automatic vending machines (AVM) in Greece was investigated. Microbiological counts (total aerobic (TAC), total psychrotrophic (TPC), Enterobacteriaceae (EC), and psychrotrophic aerobic bacterial spore counts (PABSC)) were obtained at the time of sampling and at the end of shelf-life (3 days) after storage of the samples at 4 or 8°C. TAC were found to be below the 10(7 ) CFU ml(-1) limit of pasteurized milk spoilage both during sampling as well as when milk samples were stored at either storage temperature for 3 days. Enterobacteriaceae populations were below 1 CFU ml(-1) in 69·2% of the samples tested at the time of sampling, whereas the remaining samples contained low numbers, typically less than 10 CFU ml(-1) . All samples tested negative for the presence of Listeria monocytogenes. Analogous microbiological data were also obtained by sampling and testing prepackaged, retail samples of pasteurized milk from two dairy companies in Greece (n = 26). From a microbiological standpoint, the data indicate that the AVM milk samples meet the quality standards of pasteurized milk. However, the prepackaged, retail milk samples yielded better results in terms of TAC, TPC and EC, compared to the AVM samples at the end of shelf-life. Recently, Greek dairy farmers organized in cooperatives launched the sale of pasteurized milk via AVM and this study reports on the microbiological quality of this product. The data show that AVM milk is sold at proper refrigeration temperatures and meets the quality standards of pasteurized milk throughout the manufacturer's specified shelf-life. However, based on the microbiological indicators tested, the keeping quality of the tested prepackaged, retail samples of pasteurized milk at the end of shelf-life upon storage under suboptimal refrigeration temperature (8°C) was better.