Development of potentially synbiotic fresh-cut apple slices

Alginate coatings applied on apple cubes as a vehicle for Lacticaseibacillus casei: probiotic viability and overall quality of a new functional product

BACKGROUND

Worldwide, vegan and vegetarian lifestyles, as well as food allergies and intolerance (e.g. lactose intolerance and milk protein allergy) demand the development of alternatives to dairy-based probiotic foods. In the present study, probiotic Lacticaseibacillus casei CECT 9104 was added to alginate-based edible coatings enriched with inulin and oligofructose and applied to fresh-cut apple. Microbiological, physicochemical and sensory quality parameters of the apple cubes were monitored during 8 days of refrigerated storage. Lacticaseibacillus casei was tested for its antagonistic effect against inoculated Listeria innocua and Escherichia coli O157:H7. The viability of the probiotic strain during refrigerated storage and after simulated gastrointestinal digestion (GID) was evaluated.

RESULTS

After 8 days of storage, 9.52-9.64 log colony-forming units (CFU) g-1 of L. casei were detected in apple samples. The functional apple cubes retained 8.31-8.43 log CFU g-1 of the probiotic after GID, without a significant effect of prebiotic addition. The microbiological quality and nutritional properties were maintained by the use of active coatings, whereas the sensory quality decreased after 8 days of storage. A bactericidal effect was exerted by the probiotic strain loaded in the coating against L. innocua artificially inoculated on apple cubes. Escherichia coli O157:H7 counts were reduced by 2.5 log after 8 days.

CONCLUSION

This study has demonstrated the suitability of apple cubes as an alternative matrix to milk for carrying probiotic L. casei CECT 9104 and prebiotics, offering a promising alternative for the development of plant-based functional foods. © 2024 Society of Chemical Industry.

Probiotic-loaded edible films made from proteins, polysaccharides, and prebiotics as a quality factor for minimally processed fruits and vegetables: A review

Minimally processed fruits and vegetables (MPFVs) are gaining popularity in households because of their freshness, convenience, and rapid consumption, all of which align with today's busy lifestyles. However, their exposure of large surface areas during peeling and slicing can result in contamination by foodborne pathogens and spoilage bacteria, posing potential food safety concerns. In addition, enzymatic browning of MPFVs can significantly reduce their consumer appeal. Therefore, it is necessary to adopt certain methods to protect MPFVs. Recent studies have shown that utilizing biopolymer-based edible films containing probiotics is a promising approach to preserving MPFVs. These active food packaging films exhibit barrier function, antioxidant function, and antimicrobial function while protecting the viability of probiotics, which is essential to maintain the nutritional value and quality of MPFVs. This paper reviews microbial contamination in MPFVs and the preparation of probiotic-loaded edible films with common polysaccharides (alginate, gellan gum, and starch), proteins (zein, gelatin, and whey protein isolate), prebiotics (oligofructose, inulin, and fructooligosaccharides). It also explores the potential application of probiotic-loaded biopolymer films/coatings on MPFVs, and finally examines the practical application requirements from a consumer perspective.

Non-dairy prebiotics: Conceptual relevance with nutrigenomics and mechanistic understanding of the effects on human health

The increasing health awareness of consumers has made a shift towards vegan and non-dairy prebiotics counterparts. Non-dairy prebiotics when fortified with vegan products have interesting properties and widely found its applications in food industry. The chief vegan products that have prebiotics added include water-soluble plant-based extracts (fermented beverages, frozen desserts), cereals (bread, cookies), and fruits (juices & jelly, ready to eat fruits). The main prebiotic components utilized are inulin, oligofructose, polydextrose, fructooligosaccharides, and xylooligosaccharides. Prebiotics' formulations, type and food matrix affect food products, host health, and technological attributes. Prebiotics from non-dairy sources have a variety of physiological effects that help to prevent and treat chronic metabolic diseases. This review focuses on mechanistic insight on non-dairy prebiotics affecting human health, how nutrigenomics is related to prebiotics development, and role of gene-microbes' interactions. The review will provide industries and researchers with important information about prebiotics, mechanism of non-dairy prebiotics and microbe interaction as well as prebiotic based vegan products.

Application of prebiotics in apple products and potential health benefits

Among the fruits, the apple stands out among the most used for elaboration of processed foods. However, the importance of prebiotics in apple products has never been widely analyzed. Prebiotic is a food component resistant to gastric acidity, digestion by mammalian enzymes and gastrointestinal absorption. But following fermentation in the colon, prebiotics result in specific changes in the composition and / or metabolism of the gastrointestinal microbiota, conferring benefits to the health of the host. Therefore, fortifying apple-based products with additional prebiotics is an important strategy for improving consumer health benefits. In this review, after compiling and analyzing scientific and technological studies focusing on prebiotics in apple products, the following benefits of these prebiotics became evident: (1) reduction of water loss in the food matrix; (2) preservation of bioactive and volatile compounds; (3) texture improvement (thickening) in the food industry; (4) increased shelf-live and (5) increased survival of probiotic bacteria, promoting positive effects on microbiota. In addition, this review shows the benefits of different prebiotics for stability and sensory acceptance of apple processed foods.

Bioactive edible film based on Konjac glucomannan and probiotic Lactobacillus plantarum strains: Physicochemical properties and shelf life of fresh-cut kiwis

This study investigates the efficacy of Lactobacillus plantarum strains (L. plantarum LP3, L. plantarum AF1, and L. plantarum LU5) incorporated into a Konjac-based edible coating in order to prevent fungi growth and retain physicochemical characteristics of fresh-cut kiwis kept at 4 °C for 5 days. For this purpose, probiotic survivability, fungi counts, decay percentage, color changes, titratable acidity (TA), total soluble solids (TSS), ascorbic acid content, chlorophyll amount, total phenolics, and DPPH radical scavenging of fresh-cut kiwis were evaluated. Results indicated that the population of L. plantarum strains in all treated groups retained at sufficient amounts of probiotic consumption (above 6 and 7 log CFU/g) at the end of the storage period and L. plantarum LP3 had the highest viability in comparison to other strains. The incorporation of L. plantarum in Konjac coatings markedly reduced the amount of decay and color changes and maintained the chlorophyll and ascorbic acid contents of fresh-cut kiwis compared to control samples. After 5 days of storage, total phenol content and the DPPH antiradical activities of coated kiwi slices treated with probiotics were observed about 1.2 and 10.23 g/kg compared to the pure Konjac-coated (0.84 and 7.6 g/kg) and Konjac-uncoated samples (0.44 and 4.1 g/kg), respectively. No significant difference in TSS and TA of various treatments was detected. Coated kiwi slices loaded with probiotics had higher overall acceptability compared to Konjac-coated and control samples. In addition, probiotic treatment significantly reduced mold and yeast counts compared to the control group. PRACTICAL APPLICATIONS: Recently, edible films have received more consideration as a promising method to enhance the shelf life of fresh-cut fruit. The presence of probiotics in edible films reduces the growth of spoilage microorganisms and improves consumer health. Our findings encourage the application of edible coating incorporated with L. plantarum to design multifunctional foods and preserve the qualities of fresh-cut kiwifruit.

Functionalizing and bio-preserving processed food products via probiotic and synbiotic edible films and coatings

Edible films and coatings constitute an appealing concept of innovative, cost-effective, sustainable and eco-friendly packaging solution for food industry applications. Edible packaging needs to comply with several technological pre-requisites such as mechanical durability, low permeability to water vapor and gases, good optical properties, low susceptibility to chemical or microbiological alterations and neutral sensory profile. Over the past few years, functionalization of edible films and coatings via the inclusion of bioactive compounds (antioxidants, micronutrients, antimicrobials, natural coloring and pigmentation agents) and beneficial living microorganisms has received much attention. As for living microorganisms, probiotic bacterial cells, primarily belonging to the Lactobacilli or Bifidobacteria genera, have been exploited to impart bespoke health and biopreservation benefits to processed food. Given that the health benefit conferring and biopreservation potential of probiotics is dependent on several extrinsic and intrinsic parameters, the development of probiotic and synbiotic edible packaging concepts is a quite challenging task. In the present chapter, we aimed at a timely overview of the technological advances in the field of probiotic, symbiotic and synbiotic edible films and coatings. The individual or combined effects of intrinsic (matrix composition and physical state, pH, dissolved oxygen, water activity, presence of growth stimulants or inhibitors) and extrinsic (film forming method, food processing, storage time and conditions, exposure to gastrointestinal conditions) factors on maintaining the biological activity of probiotic cells were addressed. Moreover, the impact of living cells inclusion on the mechanical, physicochemical and barrier properties of the edible packaging material as well as on the shelf-life and quality of the coated or wrapped food products, were duly discussed.

Patulin removal from synbiotic apple juice using Lactobacillus plantarum ATCC 8014

AIMS

The aim of this study was to evaluate the elimination of patulin (PAT) by Lactobacillus plantarum ATCC 8014 from artificially contaminated apple juice and its dependence on prebiotic, citric acid and ascorbic acid content.

METHODS AND RESULTS

A central composite design was used for studying each of the three factors at five levels to find the optimum concentrations. The results showed that inserting 2·3% (w/v) fructooligosaccharide, 213 mg l^-1 ascorbic acid and 1·4 g l^-1 citric acid to apple juice with inoculating 3·6 × 10¹¹ CFU per ml, L. plantarum improved the efficiency of PAT removal to 95·91% during 6 weeks cold storage. SDS-PAGE of cell surface proteins of probiotics revealed that surface layer proteins have an important role in PAT removal from apple juice. No significant difference was observed in the flavour and colour of the optimized synbiotic apple juice and in the control sample until 3 weeks of cold storage.

CONCLUSION

Lactobacillus plantarum ATCC 8014 is capable of PAT removal from artificially contaminated synbiotic apple juice.

SIGNIFICANCE AND IMPACT OF THE STUDY

Synbiotic apple juice artificially contaminated with PAT will be safe for consumers after the first day of probiotic inoculation; and surface layer proteins of probiotic cells are responsible for PAT removal.

Evaluation of postharvest calcium treatment and biopreservation with Lactobacillus rhamnosus GG on the quality of fresh-cut 'Conference' pears

BACKGROUND

Biological preservation with probiotic bacteria has arisen as an alternative to control the growth of foodborne pathogens on food. The objective of this work was to evaluate the effect of postharvest calcium application and biopreservation with Lactobacillus rhamnosus GG on the quality and bioaccessibility of total phenolic content and antioxidant activity in fresh-cut pears.

RESULTS

The immersion of whole pears in a calcium chloride solution did not provide added value. Despite the increase in observed activity of PME and PPO enzymes in fresh-cut pears during storage, the browning index and firmness values were constant for all samples. The antioxidant properties, including antioxidant activity, total phenolic content and vitamin C content, were maintained during storage, but a significant decrease was observed after in vitro simulated digestion. Ca/LGG samples showed the lowest calcium content (1.75 ± 0.00 g kg^-1 ) after 9 d of storage at 4 °C. In general, the overall visual quality scores were higher in fresh-cut pears treated with L. rhamnosus GG than in non-treated pears, with the highest values in the NoCa/LGG (7.7 ± 0.2) samples after 9 d at 4 °C.

CONCLUSION

Fresh-cut pears with a postharvest treatment of calcium and immersed in a solution containing antioxidant agents and probiotic bacteria could be a suitable alternative to dairy products for maintaining the overall quality of fruit for up to 9 d of storage. © 2018 Society of Chemical Industry.

Relationship between carbohydrate composition and fungal deterioration of functional strawberry juices preserved using non-thermal treatments

BACKGROUND

The quantification of the main carbohydrates present in strawberry juices enriched with inulin and fructo-oligosaccharides (FOS) and preserved by non-thermal techniques (vanillin and ultrasound) was conducted, in addition to an investigation of the evolution of these compounds and their relationship with fungal deterioration over 14 days of refrigerated storage.

RESULTS

A simple and environmentally friendly analytical approach based on high-performance liquid chromatography with a reflection index detector was developed for simultaneous determination of inulin, FOS and mono- and disaccharides present in the juices. When analyzing the evolution of carbohydrates during storage, a direct relationship between the consumption of sucrose and the growth of yeasts and molds (main spoilage flora in strawberry) was observed, especially in untreated samples (control). By contrast, no sucrose consumption was observed during storage of the treated sample, thus demonstrating the efficiency of the non-thermal treatments for controlling yeasts and mold growth. In turn, inulin and FOS added to juices were not degraded during storage.

CONCLUSION

The results obtained in the present study demonstrate that non-thermal treatments are adequate for preventing the growth of deteriorative flora in strawberry juices and that the addition of inulin and FOS can be a good strategy for functionalizing them, as well as improving their nutritional properties. © 2017 Society of Chemical Industry.

Applications of prebiotics in food industry: A review

Benefits of prebiotics for stimulating a healthy intestinal tract are well known. From suppression of pathogens to proliferation of indigenous bacteria of intestines, prebiotics have it all. Since the research on the scope of prebiotics is expanding, new applications are coming up every day thus upgrading the choices consumer has for a healthy living. Incorporation of prebiotics in a wide range of products that food industry offers on shelf is an innovative way to replace fat and sugars along with enhancing the mouthfeel by providing better tongue lubrication. In some cases, the thermal stability of the product is improved along with other sensory, textural and physiological benefits. This paper gives an overview of the various prebiotics available from different sources and their applications in various segments of food industry, notably dairy, beverage, processed fruit-vegetable, bakery, confectionary, extruded snack, sweetener, infant formula, pet food and livestock industry. The effects observed on addition of various prebiotics are also elaborated.

Effect of probiotics on patulin removal from synbiotic apple juice

BACKGROUND

Studies have reported the occurrence of the mycotoxin patulin in apple products. The aim of this study was to produce synbiotic apple juice and investigate the detoxification of patulin by Lactobacillus acidophilus and Lactobacillus plantarum as probiotic strains. The impact of seven process variables on efficiency of toxin removal was investigated using Plackett-Burman design and presence of the surface-layer proteins as binding site of probiotics to patulin was confirmed during 6 weeks of cold storage.

RESULTS

Results showed that the removal of patulin by probiotic bacteria from apple juice depends significantly (P < 0.05) on the fructooligosaccharide content (as a prebiotic), concentration of patulin and the addition of ascorbic acid. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of cell surface proteins of probiotic strains revealed that surface layer proteins have an important role in patulin removal from apple juice. In the best conditions, 91.23% of initial patulin concentration was removed from juice during 6 weeks refrigerated storage. No significant difference was observed in organoleptic properties of the synbiotic apple juice and raw sample.

CONCLUSION

In the best condition reported in this study, contaminated synbiotic apple juice by patulin will be safe for consumers after the first day of probiotic inoculation. © 2016 Society of Chemical Industry.

Influence of oligofructose-enriched inulin on survival of microencapsulated Lactobacillus casei 01 and adhesive properties of synbiotic microparticles

Lactobacillus casei 01 was co-encapsulated with the prebiotic oligofructose-enriched inulin at different concentrations to investigate the efficiency of the prebiotic for improving the probiotic viability. Prebiotic effect on the probiotic survival under microencapsulation conditions by spray- and freeze-drying and storage stability of encapsulated living cells at 4 °C during period of 8 weeks was evaluated. Adhesiveness of L. casei 01 loaded microparticles to pig mucin was investigated in vitro to estimate the role of microencapsulation for improving the cell adhesion ability. The microparticles produced with 3% w/w oligofructose-enriched inulin showed higher initial count, while oligofructose-enriched inulin applied at 1.5% w/w resulted in better protection of L. casei 01 under storage conditions. Further, it has been observed significantly increased pig mucin binding to microparticles compared to free probiotic cells in buffer solutions simulating GI conditions, during 24 h incubation. Hence, cell microencapsulation beside enhanced viability may allow prolonged residence time of the probiotic cells in the lower intestine through excellent muco-adhesive properties of the encapsulating materials. The results suggest synbiotic chitosan-Ca-alginate microparticles as convenient delivery system capable to ensure effective cell concentration in the lower intestine where probiotic colonization is dominant.

Fresh-cut pineapple as a new carrier of probiotic lactic acid bacteria

Due to the increasing interest for healthy foods, the feasibility of using fresh-cut fruits to vehicle probiotic microorganisms is arising scientific interest. With this aim, the survival of probiotic lactic acid bacteria, belonging to Lactobacillus plantarum and Lactobacillus fermentum species, was monitored on artificially inoculated pineapple pieces throughout storage. The main nutritional, physicochemical, and sensorial parameters of minimally processed pineapples were monitored. Finally, probiotic Lactobacillus were further investigated for their antagonistic effect against Listeria monocytogenes and Escherichia coli O157:H7 on pineapple plugs. Our results show that at eight days of storage, the concentration of L. plantarum and L. fermentum on pineapples pieces ranged between 7.3 and 6.3 log cfu g⁻¹, respectively, without affecting the final quality of the fresh-cut pineapple. The antagonistic assays indicated that L. plantarum was able to inhibit the growth of both pathogens, while L. fermentum was effective only against L. monocytogenes. This study suggests that both L. plantarum and L. fermentum could be successfully applied during processing of fresh-cut pineapples, contributing at the same time to inducing a protective effect against relevant foodborne pathogens.