Potassium Sorbate Research Articles

Exploring the Potential of Water-Soluble Squid Ink Melanin: Stability, Free Radical Scavenging, and Cd2+ Adsorption Abilities.

Squid ink melanin can be efficiently extracted from the byproduct ink sac generated during squid processing. As a natural food colorant, it possesses inherent antioxidant properties and the capability to adsorb heavy metals. This study aims to investigate the solubility of water-soluble squid ink melanin (WSSM) obtained from the ink sac, as well as its stability under various conditions including temperature, pH, salt, sugar, potassium sorbate, metal ions, sodium benzoate, sodium sulfite (reducing agent), and hydrogen peroxide (oxidizing agent). Moreover, it explores the scavenging effects of WSSM on free radicals and cadmium ions. The findings suggest that WSSM's stability is insignificantly affected by high temperature, sucrose, and salt. However, acidity, sodium benzoate, potassium sorbate, sodium sulfite (Na2SO3), and hydrogen peroxide (H2O2) significantly influence its stability. Most metal ions do not impact the stability of WSSM, except for Fe2+, Fe3+, Al3+, and Cu2+, which result in the precipitation of WSSM. Additionally, WSSM exhibits remarkable antioxidant activity with IC50 values of 0.91, 0.56, and 0.52 mg/mL for scavenging superoxide anion radicals (O2-·), hydroxyl radicals (·OH), and DPPH radicals, respectively. It also demonstrates the ability to adsorb the heavy metal Cd2+, with the adsorption rate gradually increasing with a higher temperature and larger amounts of WSSM added. Infrared spectroscopy analysis reveals the weakening of characteristic peaks (-COOH and -OH) during the process of Cd2+ adsorption by WSSM, while SEM confirms surface roughening and structural damage after Cd2+ adsorption. This study provides valuable insights for the utilization of squid melanin products as natural antioxidants and heavy metal adsorbents in the food industry.

Probabilistic modeling of the growth of Listeria monocytogenes: effect of nisin, temperature, and strain in the presence of potassium chloride or potassium sorbate

ABSTRACT The effects of temperature and nisin with either potassium chloride (KCl) or potassium sorbate on growth boundaries of three different Listeria monocytogenes strains in broth were studied. One ATCC7644 strain and two ready-to-eat food (RTE) isolates at different temperatures (4, 20, and 37°C) and nisin (0, 50, 100, 200, and 400 μg/mL) levels with either KCl (0, 1, 2, 3, and 4% w/v) or potassium sorbate (0, 0.05, 0.10, 0.15, and 0.20% w/v) were used. Highest and lowest growth probabilities were obtained for ATTC7644 and 120 (meat-based RTE isolate) strains, respectively with KCl and strain 137 (vegetable-based RTE isolate) was in between. However, the growth probabilities of the strains were just the opposite with the use of sorbate: strain 120 had the highest, whereas ATCC7644 strain had the lowest growth probability. Our results showed that nisin in combination with other preservatives may lead to diverse growth responses for different strains of L. monocytogenes. Validation studies performed in UHT whole milk and meat broth at 8 and 12°C and nisin levels of 25, 75, 150, and 250 μg/mL with either KCl (1.5%) or sorbate (0.125%) indicated 46% and 73% accurate predictions for milk and meat broth, respectively. Although a quick growth estimate was possible with the use of broth, we concluded that a model developed in a laboratory medium should not be extended in real food systems.

Investigation of the effect of ultrasonic exposure on polymer solutions in the production of biodegradable packaging materials

One of the options for improving the structure and properties of films obtained from polymer solutions is ultrasonic exposure to solutions of various chemical nature. The use of this effect on polymer solutions with various additives and agents showed not only an improvement in physical and mechanical properties, but also antibacterial properties, which contributed to an increase in the shelf life of food products. The main components of the compositions whose studies are presented in scientific articles were: polyvinyl alcohol, proteins and pullulan, they were mixed with various additives and agents, with different duration of exposure to ultrasonic treatment of solutions. The studied compositions had the following compositions: polyvinyl alcohol and hemicellulose with an antioxidant agent of tea; polyvinyl alcohol, sodium-carboxymethyl cellulose, zinc oxide nanoparticles, as well as multilayer graphene nanoplates; polyvinyl alcohol and chitosan; fish scale collagen, polyvinyl alcohol and potassium sorbate; egg white; quinoa protein and chitosan; pea protein; rice protein hydrolysate and chitosan; whey protein hydrolysate; aqueous soy extract with bee wax and essential oil of cloves; oat protein with pullulan and nizin; pullulan with the addition of nanoemulsion with cinnamon essential oil; pullulan and trehalose with tea polyphenols saturation. Some of the films made from these formulations were tested on food products such as strawberries, apples, pears and cupcakes. Based on the considered scientific data, it can be concluded that in order to improve the properties of films from polymer solutions, it is necessary to have an optimal time of ultrasound exposure to solutions, since longer ultrasonic exposure can worsen the physical and mechanical properties, namely, to reduce the tensile strength and elongation at break, in contrast to moderate exposure.

Using labelling information to evaluate the distribution of food additives in products marketed in Brazil

Food additives are ingredients added to food and beverages in order to modify physical, chemical, biological or sensory characteristics, contributing to the development of products that are safer and more convenient and attractive. Although they are widely used by food industries, little is known about the distribution of the food additives currently employed in products marketed in Brazil. Therefore, this study aimed to use labelling information of commercial food and beverages in order to identify the substances currently used by the Brazilian industry. For this, 3300 labels of 426 food items described in the Personal Food Consumption module of the Household Budget Survey (POF 2017/2018) of the Brazilian Institute of Geography and Statistics (IBGE) were searched on websites of supermarket chains and food companies as well as by visits to commercial establishments. According to the ingredient lists of the evaluated samples, 186 distinct food additives were identified. The average number of declared substances per product was between 4 and 5, with most of the labels indicating the presence of 2 or 3 additives. Considering the identified substances, 93 had an Acceptable Daily Intake (ADI) not specified or not limited and 89 were additives with a numerical ADI. Citric acid and lecithin were the most frequent substances with ADI not specified or not limited while potassium sorbate and pentasodium triphosphate were the most frequent food additives with numerical ADI. The most frequent combinations found in the evaluated samples were of potassium sorbate and citric acid, and also sodium nitrite, sodium erythorbate, and sodium diphosphate. This study demonstrates the distribution of food additives in products marketed in Brazil, allowing the creation of a comprehensive and unprecedented database, which will contribute to the evaluation of usage trends and future exposure studies for health risk assessment.

Catalytic Strategy for Conversion of Triacetic Acid Lactone to Potassium Sorbate

Catalytic Strategy for Conversion of Triacetic Acid Lactone to Potassium Sorbate

Shelf Life of Biofilm Producing PGPR Liquid Inoculants in Different Enriched Media Composition

Selecting a carrier material compatible with microbes is crucial for ensuring the quality of biofertilizers. This research aimed to identify a carrier material that could sustain the population of inoculants from dryland (including Delftia tsuruhatensis strain D9, Delftia sp. strain MS2As2, and Bacillus sp.) for a specified period. After conducting the study, it was found that a formulation of 3% molasses, 3% glycerol, 1% potassium sorbate, and 1% Tween-20 enriched with 1% nutrient was the most effective carrier material in maintaining the number of live inoculant cells. This formulation was able to sustain the population of inoculants up to the twelfth week, with a total population of 21.60 × 108 CFU.mL-1 with pH value of media is 5.29, and fulfilled the main criteria for biofertilizers.

Assessment of the bioactivity, preservation potential and sensory acceptance of a propolis extract applied in a functional fruit-herbal beverage

Functional foods and beverages can be defined as processed products that provide health benefits beyond the basic nutritional needs and reduce the risk of diseases. The design of functional products with improved shelf-life is a new challenge for the food industry. Therefore, this research aimed to: design a functional fruit-herbal beverage; compare the preservation effect of two preservatives (propolis extract and potassium sorbate) added in the beverages; evaluate the sensory characteristics of the newly designed beverages; observe the physico-chemical and microbiological changes during storage at 4℃ for 42 days. The results demonstrated that the addition of propolis extract (0.02%) in the beverage, increased the total polyphenols, total flavonoids and antioxidant activity, compared to the control beverage and the beverage containing potassium sorbate (0.05%). The results from microbiological analyses showed that potassium sorbate and propolis extract effectively inhibited the microbial growth in the treated beverages. However, the propolis extract in a lower concentration (0.02%) was as effective as potassium sorbate in a higher concentration (0.05%) during the entire storage period. Consequently, in addition to being a functional ingredient and a food enhancer, propolis is a prospective natural preservative, which can improve the shelf-life of the food products and beverages.

Evaluation of the combined effects of sodium chloride, potassium sorbate, citric acid, vacuum packaging and refrigerated storage on shelf‐life extension of desalted hake

SummaryIn this comprehensive investigation, we examined the impact of incorporating sodium chloride, potassium sorbate and citric acid, during the desalting stage to extend the shelf life of desalted hake (Merluccius hubbsi). Compared to the conventional desalting carried out in water, the desalting with the additive assayed significantly reduced total aerobic bacteria counts and extended the shelf life by threefold (from 5.7 to 21.7 days at 4 °C). After 42 days of storage in vacuum packaging, the desalted with additives hake samples showed low levels of volatile nitrogenous compounds and malondialdehyde (MDA) concentration (21.78 ± 0.56 mg TBVN 100 g−1 and 0.531 ± 0.015 mg MDA kg−1, respectively). Mechanical and colour parameters remained stable, and sensory characteristics (smell, appearance, texture, taste) did not change for 28 days at 4 °C. These findings demonstrate that the incorporation of additives into a meticulously designed three‐stage desalting process enables the production of a ready‐to‐use fishery product with an extended market life under refrigeration.

Development of plant-based fish analog: Optimization using D-optimal mixture design and fuzzy analysis, Characterization and shelf life study

This study aims to develop an analog fish product with comparable nutrients using plant-based materials such as oyster mushrooms, nori, and kombu and grade them on the 9-point hedonic scale for sensory characteristics such as appearance, aroma, juiciness, texture, and taste. Oyster mushrooms are high in protein and have an umami flavor amplified by adding seaweeds such as nori and kombu to give them a fishy flavor. The mushroom has a flaky texture that helps it resemble the fish's texture. We combined hydrated mushrooms and seaweeds with maize flour, baking powder, salt, and MSG to make the balls. The concentration of ingredients such as oyster mushroom, nori, kombu, baking powder, salt, and MSG was optimized using one-factor optimization. The final concentration of 6 % nori, 4 % kombu,24 % corn flour, 0.9 % baking powder, 1 % salt, 1 % MSG, and 63.1 % oyster mushroom using sensory data. Response surface methodology was also used to predict the appropriate model for the production of the fish analogs in which 8 % nori, 6 % kombu,23.981 % corn flour, 0.6 % baking powder, 0.81 % salt, 1.2 % MSG, and 59.4 % oyster mushroom using the D- optimal mixture design method. The sensory characteristics of vegan fish analogs were analyzed using the fuzzy scale (F1–F6), and samples were screened based on similarity values. The shelf life study was also carried out using an optimized formulation by treating with citric acid, adding preservatives like sodium benzoate and potassium sorbate, and in combination with potassium sorbate and citric acid. During the storage, antioxidant capacity, phytochemical analysis, rancidity study, moisture content, and microbial study were recorded.

Improving the post-harvest quality of fruits during storage through edible packaging based on guar gum and hydroxypropyl methylcellulose

Fruits are particularly susceptible to post-harvest decay. In this context, bio-based coatings could be a useful and sustainable approach to overcome this problem. The EU Commission is very restrictive about food additives and materials in contact with food, regulated respectively by Reg. UE (CE) 1333/2008 and Reg. UE (CE) 10/2011. In this research, different percentages of hydroxypropyl methylcellulose (H)-guar gum (G) (1–2% w/v) and potassium sorbate (PS) (0–2% w/v) were used to produce coatings to be applied on tomatoes (Solanum lycopersicum) and oranges (Citrus sinensis). The efficacy of the coatings was firstly evaluated through an accelerated test (28 °C 90% RH, 20 days) on artificially wounded fruits, and then under storage conditions (8 °C 95% RH, 6 weeks). The physical and chemical parameters of the fruits were periodically analyzed and used to evaluate the effect of the coatings on the fruit quality through a multivariate approach (PCA). All coatings were effective in preserving fruits under refrigeration against Penicillium spp. and Alternaria spp., but PS led to significant fruit weight loss despite its strong fungistatic activity. Biopolymers showed potential for preserving fruit freshness, but alternative antifungal agents without adverse weight effects should be explored using a similar statistical approach.

Exploring the potential of ume-derived proanthocyanidins: novel applications for blueberry preservation.

Proanthocyanidins (PCs) extracted from ume have many well-known functional properties. The aim of this study was to explore a novel natural food preservative using ume plum pulp proanthocyanidins (UPPP). The crude product of PCs from ume plum was obtained by using ethanol as extraction solvent and ultrasonic-assisted extraction, and then the pure product of UPPP was obtained by purification with AB-8 resin. The bacteriostatic ability of UPPP and the freshness preservation effect on blueberry were analyzed. The results showed that UPPP had a high inhibitory effect on Staphylococcus aureus (MIC of 1.563 mg/mL) and Escherichia coli (MIC of 3.125 mg/mL). Findings revealed that, in comparison to 0.02% potassium sorbate, blueberries treated with a high concentration of UPPP in a dipping treatment displayed superior quality maintenance after 7 days of storage at 4°C. Importantly, analysis of the various metrics showed that treatment with UPPP was significantly better compared to blueberries treated with 0.02% potassium sorbate. For example, the decay rate, weight loss, and total number of colonies of blueberries treated with 0.02% potassium sorbate were 55.56, 3.48%, and 4.24 ± 0.07 log CFU/mL, whereas the values of the above indexes for blueberries treated with 25 mg/mL of UPPP were 22.22, 3.09%, and 3.10 ± 0.17 log CFU/mL, respectively. Conversely, blueberries that were not dipped in any preservative displayed signs of deterioration as early as the 3rd day of the storage period, highlighting the potential of UPPP as a valuable method for preserving fruits and vegetables. Therefore, UPPP holds great promise as an innovative natural food preservative, effectively enhancing food safety, quality, and extending shelf-life.

Biodegradable cellulose acetate/layered double-hydroxide composite film for active packaging of fresh food

Biodegradable and active packaging films able to positively interact with fresh foods are extremely important to enhance the quality and the sustainability of the modern food industry. In this study, a novel biodegradable active packaging film is developed using thermoplastic cellulose acetate (CAT) and modified layered double hydroxide (LDH) as a filler. The active molecules, potassium sorbate, are ionically bonded to the LDH lamellae, resulting in delayed and controlled release system. By analysing the thermal and mechanical properties of the composites, it is found that the presence of the hybrid LDH-sorbate filler has a minor impact on the processability of the material, up to a concentration of 5% wt/wt. The kinetic release of the sorbate molecule from the composites films is evaluated using UV–Vis Spectroscopy, and analyzed by Brouers-Sotolongo kinetic equation. The active films are shown to be effective in preserving the physicochemical qualities of Pomegranate arils during storage. Overall, these results suggest that CAT active films have potential for use in the food industry to improve the shelf life and quality of fresh fruit.

Identification and control of gas-producing bacteria isolated from the swollen bagged soy sauce

The swelling of soy sauce bags seriously affects product quality and causes food safety problems, which has become an urgent problem to solve in the condiment industry. Here, gas-producing bacteria in the swollen bagged soy sauce were isolated and identified to provide an effective control method for inhibiting their growth and solving the swelling of soy sauce bags. It was found that three gas-producing bacteria isolated from the swollen bagged soy sauce were confirmed as Bacillus amyloliquefaciens (G1), Bacillus sp. (G2) and Bacillus subtilis (P3) using 16S rDNA analysis. The strains' morphologies, growth rates, and physiological and biochemical characteristics were also compared. Further studies yielded the optimal growth time, temperature and pH for the three gas-producing bacteria (B. amyloliquefacien: 24 h, 37 °C, and pH 7; Bacillus sp.: 18 h, 30 °C, and pH 6.5–7.5; B. subtilis: 36 h, 30 °C, and pH 8). Bacillus sp. was more salt tolerant than the other two. Then the antibacterial effect of the combination was tested by the physicochemical index. The results showed that filtering through a 0.22 μm inorganic micro-filtration membrane, sterilizing at 121 °C for 2 min, and adding 1 g/kg potassium sorbate was effective methods to inhibit three gas-producing bacteria and control the swelling of soy sauce.

Effect of Ginger and Garlic Marinates on Growth of Microbial Contaminants in Cold-Smoked Catfish (Clarius gariepinus) Stored at Room Condition

Aim: In this study, the preservative effect of potassium sorbate, ginger, garlic and a combination of ginger – garlic on the microbiological quality and shelf stability of cold-smoked Catfish (Clarius gariepinus) were investigated.
 Methodology: A total of 100 fresh catfish from Michael Okpara University of Agriculture, Umudike (MOUAU) Nigeria Fish Farm was used for the analysis. The fish were processed and divided into five lots of twenty each. This was followed by marinating in baths containing 0.5% potassium sorbate, 3% ginger, 3% garlic, and a mix of 1.5% ginger and 1.5% garlic each and a control for 2h. Afterwards, the treated fish was cold-smoked for 8 h and then stored at room temperature (28 ± 2°C). Fish samples were collected at 2-day intervals to determine total viable count, total fungal count, and bacterial counts (Escherichia coli, Salmonella, Staphylococcus sp, and Listeria sp.).
 Results: Findings of this study revealed that potassium sorbate, ginger, garlic, and ginger-garlic blends enhanced the microbiological safety of cold–smoked Catfish (Clarius gariepius). The result showed that although counts of some microbial contaminants increased in the cold-smoked fish, however, it varied (p˂0.05) with the treatment during storage. Comparatively, 1.5% ginger - 1.5% garlic marinate was the most effective and performed considerably higher (p˂0.05) than 0.5% potassium sorbate in the reduction of the microbial contaminants. In this study, the lowest total viable counts were observed in the 3% ginger–treated cold smoked fish (8.7x105 cfu/g) while the untreated sample was the most contaminated (1.19 x 106 cfu/g) at pre-storage. A significant increase in the total viable count was observed in all the samples during storage however, 3% garlic recorded the least (1.13 x 106 to 2.84 x106 to 3.48x106 cfu/g) and the highest in the untreated sample (1.19 x 106 to 3.38 x 106 to 3.66x 106 cfu/g). Overall, 1.5%ginger+1.5%garlic blend was most effective on E. coli while 0.5% potassium sorbate was on Salmonella at ambient storage. Listeria monocytogenes was most susceptible to all the treatment, the growth of fungi steadily increased in the treated cold smoked fish during ambient storage.
 Conclusion: The study found that 3% ginger, 3% garlic, 1.5% ginger - 1.5% garlic mixture inhibits significantly the growth of microbial contaminants relatively with 0.5% potassium sorbate in cold-smoked fish during ambient storage.

Is There any Connection Between ADHD and the Additives in Sweetened Beverages?

BACKGROUND: Sweetened beverages (SBs) have been linked to attention deficit hyperactivity disorder (ADHD), possibly because they contain sugar, caffeine, artificial colors, sweeteners, and preservatives. OBJECTIVE: The goal of this study was to show how SBs affect ADHD and to investigate the potential contribution of the various ingredients in SBs to this effect. METHODS: The study consisted of 239 children, ranging from 6 to 10 years old, divided into two groups: 111 with ADHD, diagnosed by a doctor in the Child and Adolescent Psychiatry Clinic, and 128 in the control group, who were selected from schools. The modified Food Consumption Frequency Questionnaire (FFQ) with 17 sweetened beverages was used in the assessment of beverage consumption. The consumption record was taken together with the brands of the beverages and the label information of the products was examined and the amounts of sugar, caffeine, artificial colors, sweeteners and preservatives in the beverages were calculated. Maximum food additives consumed (mg/day/kg b.w.) values of food additives were calculated according to body weight. To establish the relationship between ADHD and beverage consumption, logistic regression analysis was conducted. RESULTS: Children with ADHD consumed more fruit juice, carbonated beverages, flavored beverages, sugary milk, sugar, caffeine, sodium benzoate and potassium sorbate compared to their healthy peers (p < 0.05). The logistic regression analysis revealed that drinking fruit juice, sugary milk, carbonated beverages, and flavored drinks was significantly associated with ADHD (p < 0.01). CONCLUSION: The consumption of sweetened beverages containing sugar, caffeine, and food additives could potentially effect children’s behavior.

Effect of Some Preservatives on the Microbial Quality of Cold-smoked Catfish at Refrigerated Temperature

Aim: This study investigated the preservative effect of potassium sorbate, ginger, garlic, and a blend of, ginger and garlic on the microbiological quality and shelf stability of cold smoked Catfish (Clarius gariepinus) at refrigerated storage.
 Methodology: One hundred (100) of the freshly harvested catfish obtained from the MOUAU Fish Farm were processed and divided into five lots of 20 each. Four marinating baths containing 0.5% potassium sorbate, 3% ginger, 3% garlic, and a blend of 1.5% ginger and 1.5% garlic respectively were prepared. Each catfish lot except the fifth lot (which served as a control) was marinated for 2 h and cold smoked for 8 h. The samples were then stored for fourteen days at refrigeration temperature (4 ± 2 °C during which analyses were carried out. The Total viable count, Total fungal count, and bacterial counts (Escherichia coli, Salmonella, Staphylococcus sp, and Listeria sp) of the catfish samples before, during, and after storage were analyzed.
 Results: The total viable count (TVC) was reduced from 8.7x105 to 1.2x105 CFU/g, 1.13 x106 to 2.4x105 CFU/g, 1.09 x 106 to 2.00 x105 CFU/g, 9.60 x105 to 1.50 x105 CFU/g, and 1.19x106 to 3.00x105 CFU/g for 3% ginger, 3% garlic, 1.5% ginger +1.5% garlic, 0.5% potassium sorbate, and the control at refrigeration storage respectively. All the treatments were effective against E. coli, Listeria monocytogen, and Salmonella count. Similarly, the 3% of ginger treatment recorded counts of 1x105 CFU/g for Staphylococcus counts, during refrigeration storage. Furthermore, the total fungal count decreased for all the treatments.
 Conclusion: The study found that cold smoked catfish treated with 0.5% potassium sorbate, 3% ginger, 3% garlic and a blend of 1.5% ginger and 1.5% garlic can be stored for 14 days at refrigeration storage provided the storage condition is maintained.

Enhancing food preservation with postbiotic metabolites γ-aminobutyric acid (GABA) and bacteriocin-like inhibitory substances (BLIS) produced by Lactobacillus brevis C23 co-cultures in plant-based medium

Lactic acid bacteria (LAB) can produce γ-aminobutyric acid (GABA) with antioxidant properties and sedative effects when it binds to the GABA receptor in the human brain. LAB can also produce bacteriocin-like inhibitory substances (BLIS) with antimicrobial capabilities during carbohydrate fermentation. GABA and BLIS are natural compounds with potential health benefits and food preservation properties. Lactobacillus brevis C23 was co-cultured with three different LABs as inducers, which produced the highest GABA content and BLIS activity. They were cultured in various plant-based media to obtain an edible and better-tasting final product over commercially available media like MRS broth. A coconut-based medium with additives was optimized using response surface methodology (RSM) to increase GABA and BLIS production. The optimized medium for maximum GABA production (3.22 ± 0.01 mg/mL) and BLIS activity (84.40 ± 0.44%) was a 5.5% coconut medium containing 0.23% glucose, 1.44% Tween 20, 0.48% L-glutamic acid, and 0.02% pyridoxine. Due to the presence of GABA, the cell-free supernatant (CFS) as a postbiotic showed higher antioxidant activity than other food preservatives like nisin and potassium sorbate. Finally, microbiological tests on food samples showed that the postbiotic was more effective than other preservatives at combating the growth of LAB, molds and coliform bacteria, making it a possible food preservative.

A comparative study on the antifungal effect of potassium sorbate, chitosan, and nano-chitosan against Rhodotorula mucilaginosa and Candida albicans in skim milk acid-coagulated (Karish) cheese.

Yeasts are common contaminants in the cheese industry, which frequently arise from raw milk, the surrounding environment, and equipment, resulting in economic losses in addition to health hazards. This study aimed to compare the antifungal effect of chitosan and nano-chitosan as natural preservatives with a commonly used chemical preservative (potassium sorbate) against Rhodotorula mucilaginosa and Candida albicans. Laboratory Karish cheese was manufactured with the addition of potassium sorbate, chitosan, nano-chitosan, and their combinations at different concentrations. The survival of R. mucilaginosa and C. albicans was monitored in different treatments (CR, PR1, PR2, CR1, CR2, NR1, NR2, MR, CC, PC1, PC2, CC1, CC2, NC1, NC2, MC) during storage in a refrigerator with continuous measurement of pH. The impact of using these antifungal agents on the organoleptic parameters of Karish cheese during storage was also evaluated. There was a significant decrease in the count of yeasts in all treatments from the 3rd day of storage, while the mixture of 0.1% potassium sorbate (MR) and 2% chitosan (MC) improved the antifungal effect of chitosan with a lower potassium sorbate concentration and showed the best antifungal effects against both R. mucilaginosa and C. albicans. This combination reduced the yeast count from 8.92 and 9.57 log10 colony-forming unit (CFU)/g in MR and MC treatments, respectively, until it became undetectable on the 9th day of storage, which was earlier than for all other treatments. It was noted that the addition of chitosan nanoparticles (ChNPs) at either 0.25% (NR1 and NC1) or 0.5% (NR2 and NC2) during the manufacturing of Karish cheese significantly lowered the counts of R. mucilaginosa and C. albicans compared with chitosan with a higher molecular weight, but significantly lower than potassium sorbate until 6th day of storage as all treatments of chitosan nanoparticles became significantly higher than potassium sorbate treatments. After 9 days of storage, NR2 and NC2 treatments showed the most significant decreases in count (3.78 and 4.93 log10 CFU/g, respectively), indicating better stability of ChNPs. At the end of the storage period, PR2, PC2, CR2, and CC2 showed significantly high pH values among the groups of 4.8, 5.0, 4.8, and 5.1, respectively. The overall acceptability was significantly higher in treated Karish cheese samples than in the control group, especially at the end of the storage period. Potassium sorbate, chitosan, and ChNPs are effective antifungal preservatives against R. mucilaginosa and C. albicans. In addition, the combination of chitosan with potassium sorbate showed synergistic antifungal activity. These additives also preserve the sensorial criteria longer than for cheese without preservatives.

Classification of Food Additives Using UV Spectroscopy and One-Dimensional Convolutional Neural Network.

Food additives are utilized in countless food products available for sale. They enhance or obtain a specific flavor, extend the storage time, or obtain a desired texture. This paper presents an automatic classification system for five food additives based on their absorbance in the ultraviolet domain. Solutions with different concentrations were created by dissolving a measured additive mass into distilled water. The analyzed samples were either simple (one additive solution) or mixed (two additive solutions). The substances presented absorbance peaks between 190 nm and 360 nm. Each substance presents a certain number of absorbance peaks at specific wavelengths (e.g., acesulfame potassium presents an absorbance peak at 226 nm, whereas the peak associated with potassium sorbate is at 254 nm). Therefore, each additive has a distinctive spectrum that can be used for classification. The sample classification was performed using deep learning techniques. The samples were associated with numerical labels and divided into three datasets (training, validation, and testing). The best classification results were obtained using CNN (convolutional neural network) models. The classification of the 404 spectra with a CNN model with three convolutional layers obtained a mean testing accuracy of 92.38% ± 1.48%, whereas the mean validation accuracy was 93.43% ± 2.01%.

Contaminated Perry in Patagonia Argentina: A Case Study.

Perry is a beverage obtained by fermentation of pear juice, popular in the North Hemisphere. In Argentina it is an emerging market, particularly in the Patagonian region. The aim of this work is to describe and to evaluate the spoilage yeasts associated to six perry samples showing signs of microbiological contamination from a local craft perry company in North Patagonian region. Eighteen yeasts were isolated from four of the six perry samples where Brettanomyces custersianus, Brettanomyces bruxellensis and Zygosaccharomyces parabailii were identified. The growth capacity of these isolates in the presence of antimicrobial agents (sulfite and potassium sorbate) was analyzed in solid media. Growth parameters in sterile perry must was evaluated and the production of undesirable compounds were evaluated, products were characterized in terms of their aromatic and physicochemical features. The yeasts Z. parabailii NPCC1791 was able to grow on plates containing sulfite concentrations of up to 4mM and produced high methanol concentrations in perry. Additionally, B. bruxellensis NPPC1792 was able to produce methanol as well as high concentrations of volatile phenols including 4-ethylphenol and 4-ethylguaiacol. These results demonstrate the potential of these species as perry contaminants. Given the lack of studies describing the contaminating yeasts in perry production, this work represents the first report about perry spoilage yeasts in Argentina, with this knowledge, control strategies can be developed to prevent microbiological contamination and minimize product loss.