Experimental accelerated shelf life determination of a ready-to-eat processed food

The most direct way to estimate the shelf life of a product is to conduct simulation tests which are time consuming and expensive. Conversely, accelerated shelf life tests can be successfully used for stable products having long expected shelf life. The aim of the study was directed to verify the possibility to apply an accelerated shelf life test to perishable food products having a short-expected shelf life, such as a new ready-to-eat processed food preparation, composed mainly by cereals, tuna and chicken, packed in thermo-sealed trays and pasteurised. Different samples of the product were stored in thermal abuse conditions, collected periodically and subjected to determinations of TVB-N, pH and sensorial characteristics. Q10 and activation energy were calculated allowing to obtain a predictive evaluation of the product shelf life at the 4°C recommended temperature. The product shelf life was assessed at 26 days vs the 30 days expected by the manufacturer, showing the possibility to apply successfully ASLT for products having short shelf life, saving both time and money

Contribution of vegetables and cured meat to dietary nitrate and nitrite intake in Italian population: Safe level for cured meat and controversial role of vegetables

Nitrate and nitrite content was determined on a total of 900 samples of vegetables and cured meat and the nitrite and nitrate exposure assessment was evaluated for central Italy population based on the food consumption data reported by the national dietary surveys. The highest average content of nitrate was detected in rocket salad (4415 mg/kg) and radish (3817 mg/kg) and for cured meat in “Bresaola” (188 mg/kg) and in Bacon (178 mg/kg). The nitrite content was negligible both in vegetables than in cured meat. The average consumption among population resulted 3.45 g/kg bw/die and 0.62 g/kg bw/die for vegetables and cured meat respectively. The obtained data confirm that nitrate ADI was higher than the limits of 3.7 mg/kg bw/die for infants and was the highest exposure level for people of all ages. Cured meat consumption did not contribute to nitrate ADI exceedance neither as a mean nor as 99th percentile of exposure

Evaluation of the safety of Milano-type dry fermented sausages produced by a fast drying technology

A challenge test based on the inoculum of a multi-strain cocktail of Listeria innocua and Salmonella enterica viable cells was carried out to evaluate the capacity of an accelerated manufacturing technique (including conventional fermentation of the meat batter followed by freezing, slicing and drying) to guarantee the safety of Milano-type fermented sausages. The counts of S. enterica decreased by 1.5 and 1.6 log CFU/g in the sausages inoculated with 2 and 4 log CFU/g, respectively, while a less notable reduction (0.4 log CFU/g) was recorded for L. innocua, independently from the inoculum load. The comparison between the main microbiological and physico-chemical features of noninoculated fermented sausages, produced through either the accelerated or the traditional process, highlighted significant differences in the percent R.H. and aw values, as well as pH In both cases, the absence of Salmonella spp. and Listeria monocytogenes was ascertained. These outcomes encourage further investigation on the fate of these foodborne pathogens during a shelf-life challenge test. No differences were highlighted for the main sensory parameters analyzed

Microbial dynamics of model Fabriano-like fermented sausages as affected by starter cultures, nitrates and nitrites

The present study promotes the valorization of Fabriano-like fermented sausages, which are a central-Italy salami with an origin that dates to the early 17th century, for the possible future selection of autochthonous starter cultures to be used with respect to local traditions. To the best of the authors’ knowledge, this study represents the first attempt to define the microbial dynamics in Fabriano-like fermented sausage and the effect of nitrates/nitrites and starter cultures on its natural bacterial biota. Culture and RNA-based techniques (RT-PCR-DGGE and Illumina sequencing) were used to assess the microbial ecology of model Fabriano-like fermented sausages together with the impact of starter cultures and different nitrate and nitrite concentrations. The meat batter was used to produce two batches of fermented sausages that were prepared as follows: i) without commercial starters or ii) with the use of starter cultures composed of Pediococcus pentosaceus and Staphylococcus xylosus. Each batch was further divided into three different batches with the addition of 0/0 mg kg-1 nitrate/nitrite, 75/60 mg kg-1 nitrate/nitrite and 150/125 mg kg-1 nitrate/nitrite to the first, second and third batch, respectively. The samples, which were produced in triplicate, were analyzed on the day of production and after 7, 21, and 42 days of ripening. Enterobacteriaceae counts were always higher in model Fabriano-like sausages produced without the use of starter cultures at all of the sampling times irrespective of the tested nitrate/nitrite concentrations. Lactobacilli counts were positively influenced by the starters, although this influence was not evident over time; moreover, the effect of nitrates and nitrites on the counts of lactobacilli differed over time. As a general trend, coagulase-negative cocci counts were apparently not influenced by the tested nitrate/nitrite concentrations. Regarding the effect of nitrates/nitrites on the microbial diversity revealed by RT-PCR-DGGE, the higher the concentration, the lower the presence of some genera/species such as Pseudomonas spp., Serratia liquefaciens and Staphylococcus spp. However, Illumina sequencing detected Pseudomonas spp. as a minority species after 7, 21 and 42 days of ripening irrespective of the nitrate/nitrite concentration. The presence of Staphylococcus species was highlighted by both RT-PCR-DGGE and Illumina sequencing at all of the stages of ripening, although its presence was massively detected in fermented sausages produced without the use of nitrates/nitrites at the end of ripening. Overall, the data collected clearly highlighted the dominance of Lactobacillus sakei in all of the fermented sausages during ripening (from day 7 to day 42) and irrespective of the nitrate/nitrite concentration and added starter cultures. Moreover, Pediococcus spp. was principally detected in model Fabriano-like fermented sausage with added starter cultures irrespective of the nitrate/nitrite concentration

Evaluation of the shelf life and cooking methods of Ascoli-style olives, an Italian specialty food

In recent years, consumers have been increasingly interested in the quality and safety of specialty food products that are perceived as healthy and wholesome. However, few studies have been carried out to assess the effects of domestic cooking on the fate of pathogens in meat-based products. The present study aimed to assess the shelf life of ready-to-cook Ascoli-style olives, an Italian specialty food preparation, through accelerated shelf life tests. A challenge test was also carried out to test the efficacy of cooking methods on the survival of Salmonella Senftemberg strains. Accelerated shelf life assays, including physico-chemical assays (investigating the total volatile basic nitrogen and pH), microbiological counts (Enterobacteriaceae counts) and sensory parameters (appearance, color, odor, flavor and texture) allowed us to obtain sound information on the durability of pre-cooked Ascoli-style olives in an affordable and efficient manner. This is therefore an effective method that could be exploited by food business operators hoping to provide scientific information on product shelf life assessments. The challenge tests demonstrated that fan-baking in an electric oven at 200 °C for 12 min. and deep frying for 4 min. are the more effective treatments needed to inactivate the artificially inoculated Salmonella Senftemberg strains

Lesser mealworm (Alphitobius diaperinus) powder as a novel baking ingredient for manufacturing high-protein, mineral-dense snacks

Increasing interest in consuming foods that are high in protein, vitamin, amino acid, and mineral contents is steering growth in the market for fortified snacks. The aim of the present study was to evaluate the use of lesser mealworm (Alphitobius diaperinus) powder (LP) (at 10 or 30% substitution for wheat flour) for the protein and mineral fortification of crunchy snacks (rusks). Hence, the technological, microbiological, nutritional, and sensory characteristics of the fortified rusks were evaluated. The protein content was enriched up to 99.3% in rusks with 30% substitution; moreover, a notable increase in the essential amino acids content was observed, with histidine fortification reaching up to 129.1% in rusks with 30% substitution. The incorporation of LP has led to an enrichment of almost all the minerals considered here, and especially Fe, P and Zn, with Zn showing fortification percentages of up to 300% in rusks with 30% substitution for LP. The experimental rusks showed pleasant sensory traits and low aw values. In view of the potential industrial manufacturing of insect-based rusks, the proposed product can be assigned to level 4 (validation in a laboratory environment) of the Technology Readiness Level (TRL) scale, and it is thus ready to be tested in a simulated production environment