Low-moisture Foods Research Articles

Changes in the genomes and methylomes of three Salmonella enterica serovars after long-term storage in ground black pepper.

Low moisture foods (LMFs) have traditionally been recognized as safe for consumption, as most bacteria require higher water content to grow. However, outbreaks due to LMF foods are increasing, and the microbial pathogen Salmonella enterica is frequently implicated. S. enterica can survive in LMFs for years, but few serovars have been studied, and the mechanisms which underlie this longevity are not well understood. Here, we determine that S. enterica serovars S. Tennessee, S. Anatum, and S. Reading but not S. Oranienburg can survive in the ground black pepper for 6 years. S. Reading was not previously associated with any LMF. Using both Illumina and Pacific Biosciences sequencing technologies, we also document changes in the genomes and methylomes of the surviving serovars over this 6-year period. The three serovars acquired a small number of single nucleotide polymorphisms (SNPs) including seven substitutions (four synonymous, two non-synonymous, and one substitution in a non-coding region), and two insertion-deletions. Nine distinct N6-methyladenine (m6A) methylated motifs across the three serovars were identified including five which were previously known, Gm6ATC, CAGm6AG, BATGCm6AT, CRTm6AYN6CTC, and CCm6AN7TGAG, and four novel serovar-specific motifs, GRTm6AN8TTYG, GAm6ACN7GTA, GAA m6ACY, and CAAm6ANCC. Interestingly, the BATGCAT motif was incompletely methylated (35–64% sites across the genome methylated), suggesting a possible role in gene regulation. Furthermore, the number of methylated BATGCm6AT motifs increased after storage in ground black pepper for 6 years from 475 to 657 (S. Tennessee), 366 to 608 (S. Anatum), and 525 to 570 (S. Reading), thus warranting further study as an adaptive mechanism. This is the first long-term assessment of genomic changes in S. enterica in a low moisture environment, and the first study to examine the methylome of any bacteria over a period of years, to our knowledge. These data contribute to our understanding of S. enterica survival in LMFs, and coupled with further studies, will provide the information necessary to design effective interventions which reduce S. enterica in LMFs and maintain a healthy, safe food supply.

The influence of temperature and water activity on thermal resistance of Salmonella in milk chocolate

Salmonella contamination of chocolate-derived products has caused several outbreaks and recalls in recent years. Earlier research found that reducing moisture content or water activity of low-moisture foods sharply enhances the resistance of Salmonella during thermal treatments. However, there is a lack of data that correlates the relationship between temperature, water activity (aw), and thermal resistance of Salmonella in milk chocolate. In this study, milk chocolate was inoculated with Salmonella Enteritidis PT 30 and conditioned to aw of 0.23, 0.33, and 0.43 at room temperature (21 ± 2 °C). The chocolate samples were heated at 70, 75, and 80 °C to obtain the D-values (time to inactivate 90% of the test microorganisms at a given temperature) of S. Enteritidis PT 30. The change of aw of milk chocolates at elevated temperatures (up to 80 °C) was also investigated. The results showed that the D-value of S. Enteritidis PT 30 decreased exponentially with the increase of aw or temperature. The maximum D-value was 47.4 ± 3.7 min obtained at 70 °C and aw of 0.23. The minimum D-value was 5.2 ± 1.0 min at 80 °C and aw of 0.43. The z-values were found as the followings: zaw,70°C = 0.42, zaw,75°C = 0.36, and zaw,80°C = 0.46 °C; zT, 0.23 = 18.8 ± 2.5, zT, 0.33 = 20.6 ± 4.1, zT, 0.43 = 18.1 ± 0.5 °C. Overall, the results from this research may provide useful information to help the industry control the risk of Salmonella contamination and improve microbial safety in chocolate production.

Complete Genome Sequence of a Salmonella enterica subsp. enterica Serovar Tennessee Strain from Tahini.

ABSTRACTSalmonella sp. infections are associated with contaminated low-moisture foods (with high fat content) with increasing frequency. Here, we report the complete genome sequence of Salmonella enterica subsp. enterica serovar Tennessee, which was isolated from tahini (a paste made from ground sesame seeds) purchased at a local retailer in Berlin, Germany.

Pilot-Scale Radio Frequency-Assisted Pasteurization of Chili Powders Prepacked by Different Packaging Films

Radio frequency (RF) can penetrate most packaging films and has the advantages of pasteurizing prepackaged low-moisture foods and avoiding secondary contamination. The suitable films for prepacking chili powders and the corresponding pasteurization process are unclear. This study aimed to select a suitable film for prepackaging chili powders, optimize the parameters of RF heating prepackaged chili powders, and evaluate the effects of RF-assisted pasteurization on the quality of chili powders. The results showed that the non-woven fabric (NWF) is suitable for prepackaging chili powders by evaluating the influence of RF heating on packaging films (appearance, sealing performance, mechanical properties.). Using NWF, chili powders inoculated with Salmonella enterica Enteritidis PT 30 still achieved 6.81 ± 0.64 log CFU/g reduction, treated by RF heating at an average temperature of 67.06 °C for 7.5 min with an electrode gap of 110 mm, held for 12.5 min at a hot-air convection oven. The pasteurization process had no significant (p > 0.05) effect on the quality (appearance, volatile, and capsaicin) of chili powders. The results indicated that chili powders packed with NWF could still be effectively pasteurized by RF-assisted hot air. This study proposed a viable approach to avoid secondary contamination by adding packaging before pasteurization.

Nonenzymatic Browning of Amorphous Maltose/Whey Protein Isolates Matrix: Effects of Water Sorption and Molecular Mobility

Nonenzymatic browning (NEB) reactions often affect the nutritional quality and safety properties of amorphous food solids. Developing a proper approach to control the NEB reaction has been of particular interest in the food industry. An NEB reaction in an amorphous maltose/Whey protein isolates (WPI) matrix containing L-lysine and D-xylose as reactants were studied at ambient temperatures aw ≤ 0.44 and 45~65 °C. The results indicated that the presence of NEB reactants barely disturbed the water sorption behavior of the matrix. The Guggenheim–Anderson–de Boer (GAB) constants and Qst values of the studied samples were affected by storage conditions as the migration of sorbed water among monolayers occurred. The rate of color changes and 5-hydoxymethylfurfural (5-HMF) accumulation on the matrix were accelerated at high ambient temperatures aw, reflecting the extent of NEB reaction increases. Since the strength concept (S) could give a measure of molecular mobility, the extent of the NEB reaction was governed by the molecular mobility of the matrix as the activation energy (Ea) of 5-HMF production minimized at solids with high S values. We found that the S concept had a considerable potential usage in controlling the NEB reaction on amorphous sugar–protein solids. This data set has practical significance in the comprehensive understanding of manipulating the diffusion-limited chemical reactions on low-moisture food solids.

Sporulation and Biofilms as Survival Mechanisms of Bacillus Species in Low-Moisture Food Production Environments.

Low-moisture foods (LMF) have clear advantages with respect to limiting the growth of foodborne pathogens. However, the incidences of Bacillus species in LMF reported in recent years raise concerns about food quality and safety, particularly when these foods are used as ingredients in more complex higher moisture products. This literature review describes the interlinked pathways of sporulation and biofilm formation by Bacillus species and their underlying molecular mechanisms that contribute to the bacteriums' persistence in LMF production environments. The long-standing challenges of food safety and quality in the LMF industry are also discussed with a focus on the bakery industry.

Kinetic modeling of Maillard and caramelization reactions in sucrose-rich and low moisture foods applied for roasted nuts and seeds

A kinetic model was proposed by using a multiresponse kinetic modeling approach for Maillard and caramelization reactions in low moisture foods at neutral pH containing a moderate amount of amino acid and sucrose but a restricted amount reducing sugar. The change in the amount of sucrose, protein-bound lysine, free amino acids, and certain products of Maillard reaction was monitored during roasting of sunflower seed, pumpkin seed, flaxseed, peanut, and almond at 160 and 180 °C. A slightly different model was proposed for pumpkin seed due to its difference in compositional and physicochemical characteristics as expressed by principal component analysis. Accordingly, 3-deoxyglucosone formation via sugar degradation; 5-hydroxymethylfurfural formation from 3-deoxyglucosone and only in pumpkin seeds the conversion of N-ε-fructoselysine to glyoxal and Heyns product to 1-deoxyglucosone were found to be quantitatively important. N-ε-carboxymethyllysine and N-ε-carboxyethyllysine mainly originated through oxidation of N-ε-fructoselysine and the reaction of methylglyoxal with lysine residue, respectively.

The physicochemical properties of fruit powders and their residence time on stainless steel surfaces are associated with their ease of removal by brushing

Dry cleaning activities such as brushing, scraping, and vacuuming have been widely used in low-moisture food production. However, the impact that product compositional differences and time between cleaning cycles have on the ease of food particulate removal is unclear. In our study, fruit powders were deposited on stainless-steel coupons, then removed using a hygienic brush. The residence time was defined as the duration between fruit powder deposition and attempted removal. Longer residence time resulted in elevated water activity (aw), which decreased the degree of removal for most fruit powders other than pumpkin powder and apple powder (sieve size: 2.36 mm). For instance, the aw of peach powder increased from 0.59 ± 0.01 on day 1 to 0.64 ± 0.01 on day 7, and residual powder after cleaning increased from 86.12 ± 1.73% to 93.26 ± 2.12% from day 1 to day 7. Peach powder and apple/pear/plum powder were the most difficult to remove, with average residual powder of 92.79 ± 4.97% and 58.41 ± 11.41%, respectively. Fruit powders that were more difficult to remove also exhibited higher cohesion and adhesion. For example, the cohesion and adhesion of peach powder at 76% relative humidity for 3 days were 4479.53 ± 681.86 N/m2 and 1347.53 ± 439.15 N/m2, respectively. By contrast, the cohesion and adhesion of pumpkin powder at 76% relative humidity for 3 days were only 102.34 ± 93.80 N/m2 and 90.64 ± 36.52 N/m2, respectively. These results suggested that aw could significantly influence the brush cleaning outcome in a manner that was dependent on the identity of the fruit powder.

Effect of alkyl chain length on the antioxidant activity of alkylresorcinol homologs in low-moisture crackers

Alkylresorcinols (ARs) are a naturally occurring homologous series of phenolipids extracted from rye bran which have previously shown antioxidant activity in lipid-containing foods. This study extends previous work to consider their use in low-moisture foods using crackers as a model system. ARs (153 μmol) were capable of inhibiting lipid oxidation reactions based on the delayed generation of lipid hydroperoxides and headspace hexanal compared to a control treatment and were more effective than α-tocopherol which displayed prooxidant behavior. The antioxidant activity of ARs was observed to increase as a function of increasing alkyl chain length, with optimum activity at an alkyl chain length of C23:0; however, ARs were lost at a rate independent of alkyl chain length. A mixture of ARs displayed comparable antioxidant activity to the C23:0 and C25:0 homologs, all of which exerted stronger activity than butylated hydroxytoluene providing an effective alternative to synthetic antioxidants. These findings suggest that ARs are effective antioxidants in low-moisture foods likely because of their hydrophobicity, which allowed them to localize in the lipid phase, the purported site of lipid oxidation in the model cracker system.

Radio frequency assisted thermal processing for pasteurization of packaged whole milk powder surrounded by oil

The presence of Salmonella in milk powders has caused several outbreaks resulting in serious health problems and even deaths as well as significant economic loss due to recalls. The objective of this study was to investigate the effect of RF heating on the reduction of Salmonella in packaged whole milk powder surrounded by an oil medium. The thermal destruction kinetics (decimal reduction time; D-value) of Salmonella and Enterococcus faecium NRRL B-2354 (a potential surrogate of Salmonella for low moisture foods) in whole milk powder were determined at 75, 80, and 85 °C using thermal-death-time (TDT) cells, and the z-values (the temperature increase required to obtain a decimal reduction of the D-value) were calculated. The efficacy of the RF treatment was validated by heating the milk powder immersed in soybean oil by RF heating to 75 °C and holding it in a conventional oven for different time periods. A 5 log CFU/g reduction of Salmonella in whole milk powder was achieved after RF heating followed by 120 min holding in an oven at 75 °C. The water activity (aw) of whole milk powder significantly increased while its moisture content significantly decreased after RF heating followed by 120 min holding. A significant color change was observed after the treatment resulting in a 5 log CFU/g reduction of Salmonella. The results indicate that radio frequency heating combined with oil immersion can be used as a rapid method for milk powders to achieve the target temperature but a holding time of a few hours will be needed for a post-process lethality treatment.

Thermal death kinetics of Salmonella Enteritidis PT30 in peanut butter as influenced by water activity

It has been a challenge in developing effective thermal pasteurization processes for foods with high-fat and low-moisture contents like peanut butter, due to a general lack of reliable data on thermal resistance of pathogens in those food matrices. Recent studies on low-moisture foods like wheat flour and almond flour suggest that temperature and water activity (at the process temperatures) are two key factors that influence thermal inactivation of bacteria. In this study, we measured high-temperature water activities of peanut butter of two moisture content (MC), 3.1% and 5.6% (dry basis), and investigated the thermal death kinetics of Salmonella enterica Enteritidis PT 30 (S. Enteritidis) in those samples at 70, 80, 90, and 100 °C. The results indicated that the water activity of peanut butter increased with increasing temperature, e.g., from 0.33 and 0.53 at 23 °C, up to 0.39 and 0.59 at 100 °C, respectively. The thermal death of S. Enteritidis in peanut butter followed the first-order kinetics. Overall, higher moisture content and a higher treatment temperature led to a smaller D-value (decimal reduction time of the survival population) of S. Enteritidis. The maximum D-value was 102.6 ± 15.2 min at MC 3.1% and 70 °C, and the minimum D-value was 0.3 min (predicted) at MC = 5.6% and 100 °C. The log D-value reduced linearly with temperature at a given aw, with Z-values equal to 15.4 °C (for MC = 3.1%) and 12.6 °C (for MC = 5.6%). Based on this study, the first-order kinetic model can be employed for developing and validating thermal pasteurization processes for peanut butter. The moisture content of peanut butter and the process temperature are two key parameters that need to be controlled for sufficient lethality.

Identification of the genetic elements involved in biofilm formation by Salmonella enterica serovar Tennessee using mini-Tn10 mutagenesis and DNA sequencing

Biofilms are known to contribute to bacterial tolerance to desiccation and survival in low moisture foods. However, the molecular mechanisms underlying biofilm formation have not been fully elucidated. This study identified some of the genes that are implicated in biofilm formation by Salmonella enterica serovar Tennessee, the “peanut butter outbreak” strain. Mini-Tn10 mutagenesis was used in the study to generate random transposon insertion libraries. The ability of selected mutants in forming biofilms was compared with their wildtype parent using the crystal violet binding assay. Mutants forming significantly less (P ≤ 0.05) biofilm compared to their wildtype parent were selected for whole-genome sequencing. Mini-Tn10 insertion sites on mutant genomes were identified by comparing the acquired sequencing data with those in the Genbank using the BLAST search. In total, 56 mutants were obtained, and five were selected for further analysis according to the result of the biofilm assay. Sequencing analysis revealed that the mini-Tn10 interrupted the S. enterica genes that encode bacterial cell membrane lipoprotein, DNA topoisomerase III, attachment and invasion locus protein, bacteriocin immunity protein, and cell division protein. The information generated from the research should be useful in the control fo S. enterica in low-moisture foods and their production environments.

Alkyl chain length modulates antioxidant activity of gallic acid esters in spray-dried emulsions

Lipid oxidation is a well-recognized issue in dried food emulsions, such as infant milk formula. Antioxidants can be used to mitigate this issue; however, their efficiency in such complex systems is far from understood. In this study, antioxidant polarity is varied through the alkyl chain length of gallic acid esters (0–16 carbon atoms) incorporated to O/W emulsions that are subsequently spray-dried. During processing and subsequent storage of the samples, antioxidants with more than eight carbon atoms are effective. Both for encapsulated fat and surface free fat, we observe a slight cut-off effect, meaning that beyond eight alkyl groups, a more nonpolar antioxidant is slightly less effective. Depending on the antioxidant polarity, lipid oxidation is faster either in the encapsulated or in the surface free fat. The insights obtained contribute to understanding lipid oxidation in low moisture food emulsions, and thus lead to effective antioxidant strategies.

Modeling the effect of immersion fluids on the radiofrequency heating performance of cornflour

Non-uniform heating is a significant challenge in radiofrequency (RF) heating of low moisture foods. Previous experiments showed that the immersion of fluids (air, deionized water, and soybean oil) changed the RF heating uniformity and rate of cornflour. However, the behind mechanism is not well understood. This study developed a finite-element-based model that incorporated quasi-static electromagnetics and Fourier’s heat transfer to understand the effect of the three immersion fluids on the RF heating performance of cornflour. The model was validated and showed good agreement with experimental thermal images. The simulation results showed that the immersion of soybean oil increased the average heating rate and improved the heating uniformity compared to immersions of air and deionized water. Less distortion of electric potential reduced the fringe effect of edge heating and thus improved the heating uniformity. The higher heating rate was attributed to more dissipated power within the cornflour sample and less surface heat loss from cornflour to the surrounding fluid than the immersion of air or water. The use of soybean oil as immersion fluid could be a promising strategy to be implemented with RF technology to improve heating performance of low moisture food products.

Survival of Salmonella enterica in Military Low-Moisture Food Products during Long-Term Storage at 4, 25, and 40°C

Salmonella enterica has been increasingly implicated in foodborne outbreaks involving low-moisture foods (LMF) during the recent decade. This study aimed to investigate the potential for persistence of S. enterica in a range of LMF during storage at three temperatures. LMF products, boil-in-bag eggs (freeze-dried product), chocolate protein drink, cran-raspberry First Strike bars, mocha dessert bar, and peanut butter, were inoculated with a five-strain cocktail of S. enterica and stored at 4, 25, or 40°C for 36 months. Salmonella populations remained above 7 log CFU/g in all products stored at 4°C and above 6 log CFU/g in products stored at 25°C, excluding the cran-raspberry First Strike bars. Storage at 40°C resulted in Salmonella populations above 5.5 log CFU/g in boil-in-bag eggs after 36 months and demonstrated survivability for 12 months or less in the other five products. Additionally, a mocha bar production temperature profile study identified rapid cooling of bars in which the temperatures reached would have no measurable impact on Salmonella populations. The results indicate the ability of Salmonella to survive in a variety of LMF category foods, even under adverse storage conditions and identifies how the food matrix may affect Salmonella survivability. The data indicate the importance of establishing food processing procedures that adequately mitigate the presence of Salmonella throughout food processing systems, while also increasing comprehensive understanding of Salmonella survivability mechanisms.

Survival of Listeria monocytogenes, Bacillus cereus and Salmonella Typhimurium on sliced mushrooms during drying in a household food dehydrator

The historic view on low-moisture foods (LMFs) as safe due to the lack of microbial growth in these foods is challenged by an increasing number of reports of outbreaks and recalls caused by LMFs contaminated with foodborne pathogens. The objective of this study was to determine the survival of Salmonella Typhimurium , Bacillus cereus and Listeria monocytogenes on sliced Portobello mushrooms ( Agaricus bisporus variant Portobello) during hot-air drying (mushroom internal temperature below 45 °C) for 8 h (h) in a small household food dehydrator (250 W) and subsequent storage of the vacuum-packed dried product for 2 months at room temperature. Hot-air drying reduced the water activity (a w ) of the mushrooms to 0.17 ± 0.03 well below the limit for microbial growth. S. Typhimurium and L. monocytogenes displayed total log CFU reductions of 2.5 ± 0.4 and 2.6 ± 0.8, respectively, while B. cereus exhibited significantly ( p < 0.05) lower log reductions of 1.2 ± 0.1. Storage of vacuum-packed dried mushrooms further reduced L. monocytogenes by 2 log CFU, while numbers of viable S. Typhimurium and B. cereus were not further reduced. The higher stability of S. Typhimurium and B. cereus were reflected in the number of reports in the European Rapid Alert System for Food and Feed system of the presence of these organisms in dried mushrooms. All three organisms regrew to high concentrations when dried mushrooms were soaked overnight at room temperature, simulating a scenario where mushrooms are improperly rehydrated. Combining results from hot-air drying and subsequent storage underlines that hot-air drying and prolonged storage at low a w cannot be relied on alone to reduce the microbial and pathogen load on Portobello mushroom. • Hot-air drying reduced the water activity well below microbial growth limits. • Observed inactivation during drying could not reduce reported mushroom pathogen loads. • B. cereus and S. Typhimurium were stable in stored vacuum packed dried mushrooms. • Foodborne pathogens were able to regrow when dried mushrooms were rehydrated. • Hot-air drying and storage at low a w are not sufficient to ensure safety for dried mushrooms.

Bayesian global regression model relating product characteristics of intermediate moisture food products to heat inactivation parameters for Salmonella Napoli and Eurotium herbariorum mould spores

Thermal inactivation of pathogenic and spoilage organisms in low and intermediate moisture foods is of critical importance for guaranteeing microbiological safety and stability of these products. Producers tendentially reduce salt in low and intermediate moisture foods because of nutritional health considerations, but it is unclear how this affects microbial inactivation rates during pasteurization. In this study we predict the time to achieve a pre-defined 6-log reduction for Salmonella enterica subsp. enterica serovar Napoli (hereafter: S. Napoli) and Eurotium herbariorum mould spores (hereafter: E. herbariorum spores) and the relationship with product characteristics. We tested 31 design products for heat inactivation of S. Napoli and 29 design products for heat inactivation of E. herbariorum spores. We used a global Bayesian regression combining primary Weibull models with a secondary regression model to relate pasteurization temperature and product characteristics (water activity (aw), pH, and fractions of sodium chloride, sucrose and oil on product) to microbial counts. With this model, we predict the time to 6-log reduction. Thermal inactivation rates were much higher for vegetative S. Napoli than for E. herbariorum spores. Also, inactivation curves were non-linear for many experiments. There were significant associations between the Weibull model parameters and temperature, and pH and aw for S. Napoli and E. herbariorum spores, respectively. We parameterized an inactivation model for S. Napoli and E. herbariorum spores using design products with a broad range of characteristics and showed how the simplified approach of using D-values does not accurately describe the non-linearity of thermal inactivation for both types of organism. Results of our model can be used to produce accurate heat inactivation predictions as input for the pasteurization process in factories where intermediate moisture foods are manufactured.

Modeling the effect of protein and fat on the thermal resistance of Salmonella enterica Enteritidis PT 30 in egg powders

Microorganisms in low-moisture foods (LMFs) exhibit prolonged survivability and high heat resistance. Various external factors (water, food texture, nutritional compounds, etc.) influence the microbial heat resistance in LMFs; yet, the influential degree of each factor is not fully understood. In this study, the thermal resistance parameters (D and z values) of Salmonella enterica Enteritidis PT 30 (S. Enteritidis) at 80, 85, and 90 °C at the room-temperature water activity (aw, 25°C) of 0.32 ± 0.02 were measured. A series of egg powders with different fat and protein ratios (obtained by mixing egg white and yolk powders) were chosen as the model foods. Primary and secondary models were built from the isothermal inactivation kinetics of S. Enteritidis in the tested samples. The importance of fat and protein was then confirmed by controlling the water activity at the treatment temperature (aw, treatment temperature) via thermal water activity cells. The survivor curves of S. Enteritidis fitted well with the Weibull-type and log-linear models. The D values of S. Enteritidis increased with increasing fat (0–56.7%, w.b.) and decreasing protein contents (83.59–31.81%, w.b.). Incorporating the modified Bigelow model into the log-linear model yielded the zfat and zprotein of 58.96 and 57.14, respectively. At the controlled aw, 90°C of 0.32 ± 0.02, the D90°C values of S. Enteritidis increased remarkably (P < 0.05), but the values in egg white, whole egg, and egg yolk powders (11.73 ± 1.24, 23.82 ± 2.0, and 60.0 ± 2.4 min) were remarkably different. Our study identified that the influential degrees of fat, protein (zfat and zprotein values), and aw on the thermal resistance of S. Enteritidis in egg powders is in the order: aw,treatment temperature > fat > protein. Fat considerably increased the thermal resistance of S. Enteritidis even at the same aw,treatment temperature. This study quantified the effect of fat and protein on the thermal resistance of S. Enteritidis and emphasized the non-negligible effects of food components in LMFs’ microbial safety.

Water Activity at Isothermal Temperature and Its Effect on Microbial Heat Resistance in Low-moisture Foods

Water Activity at Isothermal Temperature and Its Effect on Microbial Heat Resistance in Low-moisture Foods

Analysis of inventions, products, technologies and equipment for the extrusion process of plant raw material

The article deals with the theoretical foundations of the extrusion process. Food extrusion can be defined as the process of mixing, homogenizing and shaping low moisture food materials and more recently high moisture food materials into intermediate or finished products by forcing them through a specially designed die. The word "extrude" comes from the Latin words "ex" (to come out) and "trudere" (to push out). Food extrusion is a state of the art high temperature short time cooking process with several other single operations such as kneading, heating, mixing and shaping in one unit. Food extrusion processing is widely used to restructure starch and protein-based food materials to produce a variety of ready-to-eat breakfast cereals: bread substitutes and pet food. The general technology for the production of extruded food products and the type of a single-screw food extruder are given. The purpose of the study was to systematize and analyze patent data on the extrusion process in the food industry. The study analyzed, systematized and summarized 79 patents on equipment, technology and products using the extrusion process. It was revealed that 46.8% of applicants are located on the territory of the Russian Federation, in 50.6% of patent documents, grain and flour is used as vegetable raw materials. The maximum number of patents were issued in 2016. The technology of products that are themselves or raw materials subjected to the extrusion process has the greatest weight in percentage terms.