Effect Of Preservation Research Articles

Improved post‐harvest preservation effects of mushroom (Agaricus bisporus) using bacterial cellulose nanocrystals‐gelatin/cinnamon essential oil emulsion coatings

SummaryThis work investigated the effect of bacterial cellulose nanocrystals (BCNCs)‐gelatin (GelA)/cinnamon essential oil (CEO) emulsion coatings (BCNCs‐GelA/CEO) on the shelf‐life extension of button mushrooms (Agaricus bisporus). CEO loadings between 1200 and 2400 μL/L were used in the coatings applied on the mushrooms' surface. The overall quality of coated mushrooms was monitored over 15 days of cold storage (4 ± 0.5 °C). Regardless of the storage time, using the highest amount of CEO within the coating formulation minimised the impact on tested parameters (weight loss, firmness, percentage of opened caps, total soluble solids, content of ascorbic acid and soluble protein, PPO/POD enzymatic activity) as compared to control samples. Interestingly, a linear relationship (R2 = 0.96 on average) between CEO concentration and the respiration rate of coated mushrooms was disclosed. Overall, this study pinpointed the capability of BCNCs‐GelA/CEO coatings to delay the aging process of button mushrooms under cold storage. Our findings could be applied to address the issue of food losses, highlighting the positive role of coating technology in enhancing the efficiency of the early stages of the food supply chain, especially in the case of button mushrooms. However, an assessment of the impact of the concentration of other coating components (BCNC and fish gelatin) on the shelf‐life extension of button mushrooms, as well as an evaluation of the coating's effectiveness in prolonging the shelf‐life of other food items, particularly non‐respiring products, is necessary to widespread the applicability of the proposed technology.

Exploring the potential of cold plasma in Optimising quality and boosting antioxidant defence in fresh‐cut bamboo shoots

SummaryCold plasma (CP) is a promising technology for fresh‐cut fruits and vegetables. In this study, the effects of CP on postharvest senescence, especially from the perspective of oxidative response of fresh‐cut bamboo shoots were examined, including the colour, firmness, lignin content, reactive oxygen species (ROS) accumulation and antioxidant enzymatic activities. CP treatments delayed the browning of bamboo shoots indicating by the increase of L* and b* values and decrease of a* value. The browning inhibition coincided with the reduction of PPO activities up to 62% by CP at 20 kV. Cellulose and lignin accumulated during storage. CP at 30 kV accelerated lignification, whereas CP at 10 and 20 kV inhibited the increase. These results were also reflected by PAL, CAD and POD activities that were enhanced by CP at 30 kV and inhibited by CP at 10 and 20 kV. The content of O2− and H2O2 was significantly increased at the first 3 days and decreased afterwards, with a similar trend of antioxidant enzymes SOD and CAT. As smaller increases in H2O2 and O2− production in CP treated samples than in control were probably attributed to elevated CP‐induced SOD activity. In addition, there was a delay effect observed in the internal parts of bamboo shoots compared with the surface (<5 mm thick). CP extended the shelf‐life of bamboo shoots by triggering the antioxidant defence. CP at 20 kV exhibited the best preservative effect on fresh‐cut bamboo shoots.

Influence of Tea Polyphenols, Chitosan, and Melatonin as the Eco-Friendly Post-Harvest Treatments on the Vase Life of the Cut Chrysanthemum ‘Pingpong’ Group

Vase life is a decisive measure of the marketability of post-harvest physiology in cut flowers. In the process of petal senescence, the cut chrysanthemum (Chrysanthemum × morifolium) ‘Pingpong’ group develops severe capitulum collapse which manifests as wilting and browning, leading to shorter vase life. Melatonin (MT), tea polyphenols (TPs), and chitosan (CT) are natural alternatives to chemical compounds with proven preservation effects. In this study, the possibility of mitigating capitulum collapse using the preservation solutions of these three eco-friendly ingredients was investigated on four varieties from the ‘Pingpong’ group, aiming to delay the senescence process. The effects on vase life of 0.02/0.04 mmol·L−1 MT, 200/400 mg·L−1 TPs, and 0.10/0.20 g·L−1 CT were, respectively, assessed with the basis of 20 g·L−1 sucrose and 250 mg·L−1 citric acid. The yellow and white varieties tend to have a longer vase life compared with the green and pink varieties. Compared to the control with only base ingredients, the greatest delay in capitulum collapse was observed with 0.04 mmol·L−1 MT in the yellow variety, maximizing the vase life to 13.4 days. MT maintained the best ornamental quality of the capitulum by decelerating fresh weight and flower diameter loss in terms of all varieties. TPs significantly increased flower diameter to improve vase life up to four more days. However, CT caused significant negative effects on vase life, with severe loss of both flower diameter and fresh weight. Therefore, the application of 0.04 mmol·L−1 MT and 200 mg·L−1 TPs was suggested to enhance the marketability of cut ‘Pingpong’, which highlighted the eco-friendly potential of post-harvest treatments.

Waste management of multiple food products through IoT enabled preservation policies and secondary supply chains

Recycling food waste (FW) into secondary products can transform the waste-to-value. This study proposes reducing FW through IoT controlled preservation and consuming it through a secondary supply chain (SSC). It explores the best policies for SSC management that recycles FW. The food chain comprises of multiple food processors for preparing multiple food products, and a common retailer where IoT based preservation curtails food deterioration. The SSC consumes the FW by recycling into multiple secondary products at multiple recycling plants and retailing at a secondary retailer. A dual channel waste collection viz. from retailers and consumers is maintained. Each product within primary and secondary supply chains (PSSCs) has a different lifetime, rate of deterioration (RoD), and preservation effectiveness. A nonlinear mathematical model is presented that optimizes decision-making for maximizing profitability. Outcomes of computational experiments demonstrate that the SSC removes 100% of the FW, conserves 89% of material resources, reduces 16% of the total cost, minimizes preservation efforts by 50%, improves replenishment cycle, and increases profitability by 39%. Some managerial insights are provided for making vital supply chain decisions.

Comparative Evaluation of Change in Organoleptic, Proximate and Vitamin Content of Freshwater Fish Species, Heteropneustes fossilis at Various Duration of Low Temperature Preservation

The present study was conducted to evaluate the effect of low temperature preservation on the sensory characteristics, proximate and vitamin content of freshwater fish species, Heteropneustes fossilis. Samples prepared from the fish were kept in low temperature for different duration and nutritional parameters were analyzed. The values of proximate composition of the sample showed the highest content for the fresh sample and the values tend to decreased with increasing storage duration except for carbohydrate. Among all the proximate parameters, moisture, protein, lipid and ash showed a content decreased during storage. However, carbohydrate showed the opposite trend, increased with storage duration. Again, among all the fat soluble vitamins, sample showed the highest value for vitamin D and lowest for vitamin E. Vitamins also showed the declining trend with increasing storage duration. From the present results, it can be stated that fresh fish sample had the highest nutrient content, therefore they should be preferably consumed over preserved fishes or if preserved, it should be for a shorter duration of time so that its nutritional content retains the same.

Effect of selective preservatives on shelf-life of guava juice extracted using pectinase enzyme

The study investigated the feasibility of enzymatic extraction for guava juice and evaluated the effects of various preservatives on its shelf life. The crushed guava puree was undergone different pectinase enzyme concentrations over three incubation periods. The findings revealed that pectinase concentrations of 0.1 % and 0.2 %, when incubated for 1 and 2 h, were the most effective. Juice yields ranged from 65.24 % to 78.64 %, with Total Soluble Solids (TSS) varying from 9.12°Brix to 11.56°Brix. The physicochemical properties of the guava juice resulted 84.2 % moisture, 2.16 % protein, 0.77 % fat, 3.27 % fiber, 0.65 % acidity, 2.25 % reducing sugars, 8.27 % non-reducing sugars, 79.53 % antioxidant activity, 173.2 mg/100g of ascorbic acid, 10.52 TSS, 109.7 mg/100g of phenolic content, and a pH of 3.2. Eight juice samples were prepared as per formulation with sodium benzoate and potassium metabisulfite (KMS) at concentrations of 150 ppm, 200 ppm, and 250 ppm, in addition to one refrigerated sample and one control. The stability of these guava juice samples was monitored every 15 days over a 90-day period. Results showed that acidity, TSS, pH, reducing sugars, and non-reducing sugars changed over time. Samples with preservatives exhibited slower changes compared to the control. Phenolic compounds diminished more quickly at ambient temperature than in refrigerated or preservative-treated samples. Initially, phenolic content and antioxidant capacity were 44 mg GAE/100g and 44 %, respectively, but declined to 10–15 mg and 15–17 % by the end of the storage period. Color changes were more noticeable in samples stored at room temperature, whereas preservatives effectively reduced color degradation caused by enzymatic browning. Moreover, ascorbic acid retention was better in samples with preservatives and those stored under refrigeration. The ascorbic acid degradation rate was highest at room temperature (0.023 day^-1) and lowest with 250 ppm KMS (0.016 day^-1). Microbiological tests indicated that the juice remained safe for 40 days at room temperature, 90 days under refrigeration, and approximately 85 days with preservatives.

Analysis of reduction of carbon emission and dynamic service policies in a green manufacturing system under isoperimetric fixed servicing budget constraint

In the recent highly saturated, fluctuated as well as competitive marketing situation, economic growth, stability and survival of a manufacturing company are substantial factors for the competent authority of a manufacturing firm. Again, due to the harmful effects of different chemicals and preservative oriented products, consumers gradually show their sensible interest towards the green products and their benefits. Furthermore, emission reduction and carbon emission tax become major issues on the sustainable growth and reputation of a manufacturing company. Fundamentally, considering these factors, this study demonstrates the prior decisions regarding best-found policy of a manufacturing company considering the effects of service with sold eco-friendly (green) products under the effects of emission taxation and reduction policies. The demand effected by level of greenness, price and dynamic service provided to the consumers. Now, due to the budget constraint, manufacturer estimates a fixed budget due to service to the consumers along with the items sold. Again, based on the carbon emission reduction policy, two distinct cases are arisen which are analyzed separately. Due to the budget constraint, maximization problem associated to the model becomes an isoperimetric control problem. Then to illustrate the realistic feasibility the proposed model, a physical example is taken under consideration and it is solved using Teaching–learning-based optimization algorithm (TLBOA) considering each of the cases. Finally, the sensitivity analyses are performed to get some important implications for the manager of the proposed manufacturing system.

An Intelligent, Solar‐Responsive, and Thermally Conductive Phase‐Change System Toward Solar‐Thermal‐Electrical Conversion Featuring Daytime Blooming for Solar Energy Harvesting and Nighttime Closing for Thermal Preservation

AbstractTo alleviate resource shortage and environmental pollution, solar energy can be converted into thermal energy stored in phase change materials and in turn generate electrical energy. To enhance the solar energy utilization efficiency of solar‐thermal‐electrical conversion devices and prevent the heat loss to the environment at night, an intelligent solar‐responsive phase‐change system is innovatively designed consisting of a graphene aerogel film/paraffin wax stamen with an ultra‐high thermal conductivity of 46.7 W m−1 K−1, and thermally preserving aerogel film/liquid crystal elastomer bilayer petals that can bend solar‐responsively by the synergistic effect of solar‐thermal energy conversion and heat‐induced contraction. The solar‐responsive phase‐change system achieves daytime blooming for solar‐thermal conversion with simultaneous energy storage and nighttime closing for minimizing heat loss to the environment, exhibiting a high solar‐thermal conversion and energy storage efficiency of 89.4% and delaying its temperature drop by the thermal preservation effect of the petals. The assembled solar‐responsive solar‐thermal‐electric generator can reach an output voltage of 1033.8 mV at a light intensity of 500 mW cm−2 and continue to generate electrical energy during nighttime, holding tremendous promise in efficient solar energy conversion, storage, and utilization.

Ethyl cellulose matrixed poly(sulfur-co-sorbic acid) composite films: Regulation of properties and application for food preservation

Developing non-toxic and sustainable materials with versatile and diverse functions has always been a crucial issue in food preservation packaging. Recently, inverse vulcanization has emerged as a precise and eco-friendly solution, attributed to the versatility of resulting polysulfides. In this study, a polysulfide crosslinked with sorbic acid was prepared by inverse vulcanization, and further combined with bio-macromolecular ethyl cellulose to form composite films via a casting method. Thanks to the ethanol-solubility and good compatibility of ethyl cellulose towards the polysulfide, morphology of the films can be tailored by adjusting the component ratio, thereby achieving favorable water vapor permeability (2.20 × 10−12 gs−1m−1Pa−1), oxygen permeability (4.01 × 10−4 gs−1 m−2), elasticity modulus (~400 MPa), elongation at break (~16 %), etc. Some films demonstrate remarkable antibacterial activity against a broad spectrum of bacteria and fungi, demonstrating their effectiveness in food preservation. The browning and spoilage of preserved Agaricus bisporus were inhibited, with 79.2 % of the initial firmness retained and a 5.6 % weight loss recorded on the 6th day. For the 15-day preservation of grapes, minimal changes in appearance, firmness, or TSS were observed, underscoring the promising potential of this composite for food preservation applications.

Application of Nanotechnology to Enhance the Effectiveness and Stability of Essential Oils

The global demand for essential oils is expanding as a result of their numerous applications and increasing consumer exposure in the international market. Essential oils (EOs) are mixtures of volatile compounds including, but not limited to, phenolics, esters, ketones, terpenes, alcohols, and amides. The majority of EOs have excellent antioxidant, antibacterial, and functional activities. These natural products have conquered space in the food, drug, and cosmetic commercial arena. Unfortunately, like many lipophilic and aromatic active substances, EO presents some drawbacks such as low water solubility, strong organoleptic characteristics, low stability, and limited administration routes, which confines their Industrial use. EOs can be nanoencapsulated to increase their persistence, and bioavailability in the biological process by employing the optimum encapsulation polymers. Additionally, these particles are capable of controlling the release of the EOs promoting a prolonged preservative effect in cosmetics and foods, as well as a potential advantage for pharmaceutical dosage forms. The current research focuses on the essential features of EOs as well as their encapsulation methods. Furthermore, the potential applications of applying nanoencapsulated essential oils in the healthcare field were addressed.

Anti-biofilm and antioxidant activities of Sargassum muticum extracts and their preservation effect of Chinese shrimp (Penaeus chinensis)

Vibrio parahaemolyticus can enhance bacterial resistance to disinfectants and antimicrobials by forming biofilms. The development of new natural antimicrobials is essential for the control of biofilm-related contamination and infection. In this paper, we preliminarily explored the inhibitory activity of Sargassum muticum extracts (HA-PTs) against the biofilm of V. parahaemolyticus. HA-PTs exerted anti-biofilm activity by destroying the integrity of the cell membrane, curbing the motility of single and colonial bacteria, hindering the synthesis of polysaccharide intercellular adhesion, inhibiting the secretion of extracellular DNA, and reducing the metabolic activity of biofilms. Furthermore, experiments on four free radicals (DPPH•, •OH, ABTS+•, and O2−•) scavenging activity and total antioxidant capacity (FRAP method and phenanthroline method) demonstrated that HA-PTs have strong reducing properties and can capture a variety of free radicals, which in turn prevents them from participating in oxidative reactions. When HA-PTs were applied to Chinese shrimp infected with V. parahaemolyticus, it could prolong their shelf life by controlling the pH rise caused by protein degradation, inhibiting the bacterial proliferation, reducing the content of total volatile basic nitrogen produced by protein degradation, and reducing the accumulation of thiobarbiturates caused by oxidative deterioration of fats.

Antimicrobial guar gum films optimized with Pickering emulsions of zein-gum arabic nanoparticle-stabilized composite essential oil for food preservation

In this study, composite essential oil Pickering emulsion stabilized with zein-gum arabic (GA) nanoparticles (ZGCEO) was prepared to improve the characteristics of guar gum (GG) films. ZGCEO exhibited commendable stability and compatibility with GG, while leading to a noticeable improvement in the light barrier (from 3.98 A mm−1 to 17.09 A mm−1) and water vapor barrier characteristics of GG films, concomitantly mitigating their hydrophilic nature, with decreasing moisture content (from 17.70 % to 10.50 %), water solubility (from 84.41 % to 71.79 %), water vapor permeability (from 5.64 × 10−11 g (m s Pa)−1 to 4.97 × 10−11 g (m s Pa)−1), and an increasing water contact angle (from 69.8° to 94.2°). The addition of 2 % ZGCEO yielded a notable increase in the tensile strength of the GG-ZGCEO films, but the elongation at break decreased with increasing ZGCEO concentration. Moreover, the incorporated ZGCEO demonstrated outstanding antioxidant and antimicrobial characteristics, featuring a slow-release behavior of essential oil. The GG-ZGCEO coating also showed an excellent preservation effect in pork and “Huangguan” pears during storage. Collectively, we substantiated the efficacy of ZGCEO in augmenting the functional attributes of GG films, thereby establishing their potential utility as antimicrobial packaging materials conducive to food preservation.

Reading the Smoked Fish MSME Market Competition Map Through Analysis of Porter's Five Forces of Perception

Fisheries are a superior commodity and are still a favorite on the world market. Processed seafood that is quite interesting to discuss is smoked fish. The smoking activity itself provides several benefits, including: providing a preservation effect on fish meat, improving the taste of fish, and utilizing excess catches during the abundant fishing season. In the journey of Smoked Fish UMKM, of course there are various obstacles faced, including decreased turnover, lack of technological capabilities and marketing networks. Porter's Five Forces can be used to identify industry-specific competitive strategies for businesses. For Jrakahpayung smoked fish MSMEs to overcome the challenging competitive environment, competitive strategy planning is very helpful. Based on the analysis, Jrakahpayung smoked fish MSMEs are not too affected by the threats posed by business competitors because there are only a few comparable MSMEs. However, because the quality of the raw materials used must always be maintained so that consumers are loyal to Jrakahpayung smoked fish products, the threat to buyers and suppliers is quite high. On the other hand, consumer purchasing power automatically decreases if suppliers do not provide high quality raw materials. The total value of the threat of new entrants is 2.4 medium, the bargaining power of buyers is 3.5 high, the threat of substitutes is 1.9 low, the bargaining power of suppliers is 4.8 high, competition between existing competitors is 2.4 medium.

Highly stable and multifunctional intelligent film based on grape skin anthocyanin, polyvinyl alcohol, chitosan and selenopeptide: Preparation, characterization and application

Highly stable and multifunctional intelligent films were fabricated using a combination of grape skin anthocyanin, polyvinyl alcohol, chitosan and selenopeptide, and the influence of selenopeptide concentration on films' properties and their effectiveness in strawberry preservation and freshness monitoring was investigated. The results showed that the incorporated selenopeptide could interact with polyvinyl alcohol and grape skin anthocyanin via hydrogen bonding, improving the hydrophobic, UV-blocking, and mechanical characteristics of the films. In particular, the introduction of 0.4% selenopeptide into the film notably boosted its tensile strength from 11.91 MPa to 26.91 MPa. More importantly, the films incorporated with selenopeptide showed decent antioxidant and antibacterial properties, along with high storage stability and thermal stability. Adding 0.4% selenopeptide to the film can increase the shelf life of strawberries at 25 °C by 3 days, and a distinct color change showing fair good linear relationship with the freshness indexes of the strawberry (hardness and weight loss rate) was observed. Overall, anthocyanin-infused films combined with selenopeptide have demonstrated promising results in preserving food and monitoring freshness, opening up new opportunities for preparing stable, smart and active films.

Experimental assessment of ozonated ice: Preparation, stability, and preservation effects on shrimp (Metapenaeus ensis)

Ozonated ice not only retains the inherent performance and function of ozone, but also serves as a cold source for food preservation. However, its preparation is challenging due to the low solubility and instability of ozone in water. So here, the major preparation techniques and the storage stability of ozonated water and ice were studied. Besides, the impact of ozonated ice treatment on the quality of shrimp (Metapenaeus ensis) was explored. To achieve these ends, a set of ozonated ice preparation devices was established, and the optimal conditions for producing ozonated water and ice were confirmed as follows: using 0 °C deionized water as the water source, achieving an outlet flow rate of 80 L/h, cyclically mixing gas-liquid twice, adding 1.0 g/kg of polyoxypropylene oxyethylene glycol ether (POGE), and freezing at −80 °C. Regarding ozone stability, an increase in initial ozone concentration and storage temperature, along with a decrease in water purity, resulted in a shorter half-life of ozone in water. Additionally, a lower storage temperature was conducive to prolonging the half-life of ozonated ice, while the addition of POGE had little effect. In practical application, under the optimal conditions for producing ozonated water and ice without POGE, shrimp stored in ozonated ice demonstrated superior sensory scores, whiteness values, and shear force compared to those stored in normal ice. Concurrently, they displayed reduced levels of TVC, TVB-N, and pH. Furthermore, the application of ozonated ice treatment mitigated blackening and improved odor quality. Consequently, this research offers a scientific foundation for the industrial application of ozonated water and ice and serves as a reference for preventing the deterioration and quality loss of shrimp and other seafood products.

Enrichment of Peanut butter using Curcuma Longa (turmeric) industrial byproducts and its impact on shelf life

This study explores the potential of Curcuma longa byproducts, called Curcuminoid removed turmeric oleoresin (CRTO), to extend the shelf life of peanut butter. CRTO, rich in curcuminoids, was added to peanut butter formulations to assess its preservative effects, flavour impact, and nutritional benefits. Results demonstrated that CRTO oil and curcuminoids effectively prolonged peanut butter shelf life by delaying rancidity. The study also compared results using oxygen scavenger film (OSF) packaging. Over time, water activity and oil separation increased, but CRTO oil and OSF helped to mitigate these effects. Sensory evaluations favored CRTO oil and curcuminoids, while microbial analysis confirmed safety of both the control and OSF samples for six months at 27 °C and 65% RH, and for four months at 37 °C and 95% RH. This study proposes a natural and sustainable method for extending peanut butter shelf life while enriching it with curcuminoids, with significant implications for the food industry.

Effects of quaternization sites and crossing methods on the slow-release and antibacterial effects of hydroxypropyltrimethyl ammonium chloride chitosan/dialdehyde chitosan-based film

In this study, the active food packaging film were prepared using hydroxypropyltrimethyl ammonium chloride chitosan with different substitution sites (O-HACC & N-HACC) and dialdehyde chitosan (DCS) grafted with protocatechuic acid (PA). To explore the effect of chitosan quaternization positions and crosslinking approaches on the slow-release and antibacterial properties, the double-crosslinked film were fabricated through the self-coupling reaction of PA and Schiff base reaction between amino groups on HACC and aldehyde groups on DCS. The HACC/DCS-based film exhibited stable porous three-dimensional networks with high nisin loading ratios (>90 %). With the participation of the catechol-catechol structure, the dense double-crosslinked film effectively restricted the diffusion of the water molecules, resulting in excellent slow-release properties fitting with the Korsmeyer-Peppas kinetic model. Especially, O-HACC/PA-g-DCS film, which had more reaction sites for Schiff base crosslinking than N-HACC, exhibited the equilibrium swelling ratio of 800 % at 60 h and could sustainably release nisin via non-Fickian diffusion behavior until 48 h. Moreover, the HACC/DCS-based double-crosslinked film performed good long-time antibacterial activity and preservation effects on salmon. On the 10th day of storage, the TVBN of N-HACC/PA-g-DCS and O-HACC/PA-g-DCS groups were only 28.26 ± 1.93 and 29.06 ± 1.68 mg/100 g and still lower than the thresholds.

Effectiveness of Selected Preservatives in Protecting Bamboo Against Termite Attack

Bamboo is highly susceptible to insect attacks. To promote its use as an alternative to wood, it is crucial to assess its preservation methods to increase its service life. This study investigated the effectiveness of preservatives in protecting bamboo against termite attack. Three bamboo species were extracted, air-dried, and pressure-treated with different concentrations of crude-lake salt, borax-boric acid, and tanalith. Preserved and unpreserved samples for each treatment were weighed and exposed to Macrotermes bellicosus termites in Kasagala Central Forest Reserve. After 21 days, durability classes and mass loss were determined following European standards. The results showed that termite resistance depends on the type of preservative. All the untreated and crude lake salt-treated bamboo samples were attacked and classified into the not-durable class. Samples treated with Tanalith were classified under the durable class. Borax-boric acid provided moderate resistance to bamboo samples and belonged to the moderately durable class. Crude lake salt did not provide sufficient protection against termites. The difference in species did not influence termite resistance. Untreated B. vulgaris had the highest mass loss and O. alpina the lowest. The findings from the study will contribute to improved utilisation of bamboo by proper preservation

High-value extracts from pulp, seeds, and leaves of Grumixama: Antioxidant, low cytotoxic, and preservative effect in cream cheese

This study aimed to optimize the extraction of bioactive compounds from the pulp, seeds, and leaves of grumixameira (Eugenia brasiliensis Lam.) and evaluate its antioxidant and cytotoxic effects for direct use in creamy cheeses for conservation purposes. Through the response surface methodology, the best mixtures of solvents (water:ethanol:acetone volume fractions) were identified for each plant part: pulp (0.42: 0.16: 0.42), leaves (0.49: 0.26: 0.25) and seeds (0.54: 0.30: 0.16); which promoted an increase in the yield of the extraction of bioactive compounds. Leaves extracts showed the greatest index of total phenolic content (187.03 mg GAE/g) and highest antioxidant activities through DPPH (486.55 mg Trolox/g) and FRAP (680.81 mg ferric sulfate/g) assays. The pulp extracts, in turn, presented the highest indexes of content of total flavonoids (20.17 mg QE/g) and total anthocyanins (62.32 cyanidin-3-glucoside/g). The high-performance liquid chromatography (HPLC) analyses identified quercetin as the major compound in all extracts, followed by catechin. The rutin also stood out in leaves and pulp extracts.The extracts obtained from the leaves and pulp of grumixama showed a low cytotoxic effect on human embryonic kidney cells. Using the three optimized extracts in creamy cheeses contributed to preserving the physical-chemical and microbiological characteristics, emphasizing the leaves extracts when used at a concentration of 2 wt %. Thus, the results obtained in this study demonstrated the bioactive potential of these natural extracts, which can be exploited for technological applications in the food and pharmaceutical industries.

Reduction of Total Phenols in Virgin Olive Oil as a Preservation Medium during Cold Storage of Whey Cheese and Tofu.

Virgin olive oil, known as a good source of health-promoting hydrophilic phenols, is traditionally used as a medium for preserving various foods. Phenols in general can form complexes with proteins, but there is little information on the direct contact of virgin olive oil with protein-rich food during long-term storage. In this study, the dynamics of the decline of total phenols in oil used as preservation medium for a traditional (whey cheese skuta) and a modern product (tofu) were compared. Pieces of skuta or tofu immersed in virgin olive oil at different food-to-oil mass ratios were stored in the refrigerator for up to 21 days. The oil quality indices, water content and the total count of aerobic mesophilic bacteria in the immersed materials were monitored. To determine the total phenols in the oil, the optimal conditions of the Fast Blue BB test, which is a suitable alternative to the standard method, were tested and selected. The effect of both materials on the indicators of hydrolytic and oxidative deterioration of the oil is almost identical (a gradual decrease), which is most likely due to the continuous release of water from the immersed food. A sharp decrease in total phenols in the oil (by about 50 %) after seven days of storage in contact with both materials indicates a combination of causes (water-to-oil migration and phenol-protein interactions). The form of the rational function is highly representative of the decrease in total phenols during the first seven days of tofu/oil storage, indicating a very rapid interaction with tofu proteins. The preservative effect of virgin olive oil in terms of microbiological spoilage was not observed. The results of this study contribute to the knowledge on the dynamics of phenol-protein interactions and emphasise the need for further investigations on traditional or newly used protein-rich foods preserved in direct contact with virgin olive oil, taking into account possible changes in the functional, nutritional and sensory properties of phenols and proteins.