Quality,functionality, and microbiology of fermented fish: a review

Abstract

Fermentation is a traditional food preservation method and is widely used for improving food safety, shelf life, and organoleptic and nutritional attributes. Fermented fish are produced and consumed in different parts of the world and are an integral part of many food cultures. Furthermore, fermented fish are a source of interesting microbes and are an important industry in many countries. This review tries to update the types and manufacturing processes for fermented fish around the world. The emphasis is on this work related to fermented fish and their health benefits, as well as the contribution of microorganisms to their fermentation. A variety of different approaches have been used to determine and understand microbial composition and functionality. Moreover, some challenges and future research directions regarding fermented fish are also discussed in this review. Further research into fermented fish products is of crucial importance not only for the food industry but also for human health. However, extensive in vivo and toxicological studies are essential before the application of bioactive-rich fermented fish products for human health benefits.     

Impact of plant essential oils on microbiological,organoleptic and quality markers of minimally processed vegetables

The objectives of this study were to evaluate the efficacy of plant essential oils (EOs) for control of the natural spoilage microflora on ready-to-eat (RTE) lettuce and carrots whilst also considering their impact on organoleptic properties. Initial decontamination effects achieved using EOs were comparable to that observed with chlorine and solution containing oregano recorded a significantly lower initial TVC level than the water treatment on carrots (p < 0.05). No significant differences were found between the EO treatments and chlorine considering gas composition, color, texture and water activity of samples. The sensory panel found EO treatments acceptable for carrots throughout storage, while lettuce washed with the EO solutions were rejected for overall appreciation by Day 7. Correlating microbial and sensory changes with volatile emissions identified 12 volatile quality markers. Oregano might be a suitable decontamination alternative to chlorine for RTE carrots, while the identification of volatile quality markers is a useful complement to sensory and microbiological assessments in the monitoring of organoleptic property changes and shelf-life of fresh vegetables.Industrial relevanceThere is industrial demand for natural alternatives to chlorine, which is commonly used for decontamination of fresh produce but which has limitations with respect to antimicrobial efficacy and possible formation of carcinogenic compounds in water. Plant essential oils have proven antimicrobial and other bioactive properties, however their usefulness in foods can be mitigated by their high sensory impact. This study examined the application of EOs for fresh produce decontamination addressing control of spoilage microflora and improving shelf-life characteristics whilst also considering the impact on organoleptic properties. The effectiveness of oregano as a decontamination treatment was comparable with that of chlorine. Carrot discs treated with the EO regimes were acceptable in terms of sensory quality and appreciation, therefore oregano could offer a natural alternative for the washing and preservation of fresh produce. Combining EOs with other natural preservatives might minimize doses and reduce the impact on organoleptic properties of fresh vegetables.     

Occurrence,types, properties and interactions of phenolic compounds with other food constituents in oil-bearing plants

ABSTRACT

Phenolic phytochemicals have become of interest due to their therapeutic potential, particularly with regards to their anti-cancer, anti-inflammatory, hypolipidemic, and hypoglycemic properties. An evolving area of research involving phenolics in foods and their products pertains to the functional, biological, and nutritional consequences resulting from the binding between certain phenolic compounds and the macronutrient and micronutrient constituents of foods. The goal of this review is to provide a summary of studies investigating endogenous phenolic interactions with major components in food systems, including carbohydrates, proteins, lipids, minerals and vitamins, with a focus on the phenolic compounds and nutrients in oil-bearing plants. Another major objective is to provide a comprehensive overview of the chemical nature of phenolic interactions with food constituents that could affect the quality, nutritional and functional properties of foods. Such information can assist in the discovery and optimization of specific phenolic complexes in plant-based foods that could be utilized towards various applications in the food, nutraceutical and pharmaceutical industries.     

Biotransformation of durian pulp by mono- and mixed-cultures of Saccharomyces cerevisiae and Williopsis saturnus

Durian is a seasonal tropical fruit widely grown and highly prized in Southeast Asia. This is a first study to assess the transformation of durian constituents during fermentation with mono- and mixed-cultures of Saccharomyces cerevisiae and Williopsis saturnus with a view to developing a novel alcoholic beverage. A diversity of volatiles was produced especially alcohols and esters, while those volatiles initially present in durian, particularly the character-impact sulphur-containing odorants, were transformed. Most of the sulphur-containing compounds decreased with fermentation. 3-(Ethylthio)-1-propanol was produced initially then remained relatively stable, whereas ethyl thioacetate was formed initially then decreased in all culture types. The kinetic changes and concentrations of volatile compounds were similar in both the mixed-culture and the S. cerevisiae monoculture, except for higher amounts of alcohols in the mixed-culture. The W. saturnus monoculture, on the other hand, was the main producer of acetate esters. Sensory evaluation revealed a strong sulphury note retained in all fermentations but less unfavourable metallic and yeasty notes in the mixed-culture. The study suggests that biotransformation by yeasts can be effective in modifying the constituents and modulating the organoleptic properties of durian.     

Anti-proliferative,pro-apoptotic and anti-oxidative activity of Lactobacillus and Bifidobacterium strains: A review of mechanisms and therapeutic perspectives

Abstract

Lactobacillus and Bifidobacterium strains, their isolated constituents and substances that they secrete exert various anti-cancer actions, resulting from their anti-proliferative, pro-apoptotic and anti-oxidant properties. They can express and secrete anti-oxidant enzymes, bind reactive oxygen species, release small molecular weight anti-oxidants and chelate transition metals, preventing detrimental actions of many carcinogens. Lactobacillus and Bifidobacterium can interact with proteins regulating the cell cycle inhibiting proliferation of cancer cells, which often are intrinsically resistant to apoptosis. Lactobacilli and bifidobacteria can break this resistance through activation of pro-caspases and downregulation of the anti-apoptotic Bcl-2 and upregulation of pro-apoptotic Bax proteins. Anti-cancer effects of these bacteria can be also associated with their multi-pathways action in the microbiota. However, exact mechanism of their anti-cancer action is poorly known and needs further studies, which are justified by the important role of these bacteria in cancer biology as well as their potential preventive and therapeutic use.     

Effect of high pressure treatment applied on starter culture or on semi-ripened cheese in the quality and ripening of cheese in brine

Cheese ripening acceleration is of continuous interest for the industry. High-pressure (HP) treatment of starter cultures used in cheese-manufacturing offers the potential to accelerate ripening by increasing the activity of their intracellular peptidases that contribute in the development of desired cheese organoleptic characteristics.The objective of the present research was the investigation of the effect of HP treatment (200 MPa-20 °C - 20 min) directly on white brined cheese or on the starter culture used for its manufacture (Str. thermophilus:L. lactis:L. bugaricus 2:1:1). For this purpose, the microbial, textural, physicochemical and organoleptic characteristics and proteolysis were assessed during the 2nd stage of ripening in cold stores. Control cheese without any treatment was also studied.Cheeses made with HP-treated starters had increased secondary proteolysis. Organoleptic scoring of these cheeses was higher during the whole storage period compared to control and HP-treated cheese. Their superiority was evident even at the early stages of ripening in cold stores, since no bitterness was detected. On the contrary, although HP treated cheeses showed the highest increase in aminopeptidases activities, this was not correlated with the studied ripening indices or the organoleptic characteristics.According to the results, HP-treated starter culture can accelerate proteolysis and potentially the ripening of cheese-in-brine.Industrial relevanceThe data obtained from this work suggest that application of HP treatment under optimized conditions on cheeses in brine starter cultures or on whole cheeses can be effectively used for the production of products with reduced ripening time. This is of great importance for the cheese industries, since the storage period for ripening is long (higher than two months), while applying HP treatment as suggested in this study, this time may be reduced to less than one month, producing cheeses of superior quality.     

Microwave irradiation of hazelnuts for the control of aflatoxin producing Aspergillus parasiticus

In this study, the effects of microwave treatment on hazelnuts artificially contaminated with aflatoxigenic fungi were evaluated qualitatively and quantitatively. The physical quality attributes (color, moisture loss, and sensory attributes) of microwave treated hazelnuts were also evaluated. A significant 3-log reduction in Aspergillus parasiticus contamination was observed after 120 s treatment, no or similar changes were observed during the storage of microwave treated hazelnuts under the storage conditions. While taste and odour of microwaved in shell hazelnuts were unaffected during treatment and subsequent storage, microwave treatment duration of 120 s was found to be capable of reducing fungal count of A. parasiticus on in-shell hazelnut without any noticeable change in nutritional and organoleptic properties of nuts. Based on this and the earlier study, a hybrid process is proposed, where UV-C surface treatment and vacuum assisted microwave are combined with air drying to increase the shelf life and control the quality.Industrial relevanceA hybrid industrial process is proposed, where UV-C surface treatment and vacuum assisted microwave treatment are combined to increase the shelf life and control the quality of hazelnuts.     

Inhibitory effect of thyme and basil essential oils,carvacrol, thymol,estragol, linalool and p-cymene towards Shigella sonnei and S. flexneri

There are a few reports on the antimicrobial activity of essential oils or their major constituents towards Shigella sp. The antimicrobial effect of basil and thyme essential oil and its major constituents thymol, p-cymene, estragol, linalool, and carvacrol was determined using the agar well diffusion assay. Thyme essential oil and thymol and carvacrol showed inhibition of Shigella sp. in the agar well diffusion method. The potential of thyme essential oil, thymol and carvacrol at 0.5% and 1.0% v/v for decontamination of lettuce was evaluated. A decrease of the shigellae was observed after washing with 0.5% while at 1% Shigella numbers dropped below the detection limit. However, the antimicrobial effect on a subsequent lettuce sample in the same decontamination solution was significantly decreased. In addition, application of thyme essential oil or thymol or carvacrol for decontamination is hampered by sensoric properties of the lettuce (browning, strong odour).     

The Influence of Pectin from Apple and Gum Arabic from Acacia Tree on the Quality of Pizza

The aim of this work was to determine the effect of apple pectin and arabic gum on the organoleptic characteristics of pizza flans. Significant differences in the sensory characteristics, such as flavour and change during chewing as well as the quality between the pizza flan with the addition of hydrocolloids and the pizza flan without them were found out. The additions of hydrocolloids improve the quality and flavour of pizza flans. On the other hand, higher amounts of gum arabic from the acacia tree caused worse tenderness of the bakery product.      

Comparative study of nanoemulsions based on commercial oils (sunflower,canola, corn,olive, soybean,and hazelnut oils): Effect on microbial,sensory, and chemical qualities of refrigerated farmed sea bass

The effects of oil-in-water nanoemulsions using different commercial oils (sunflower, canola, corn, olive, soybean, and hazelnut oils) on the sensory, chemical (total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARs), peroxide value (PV), free fatty acids (FFA), water holding capacity (WHC), and pH) and microbiological qualities (mesophilic aerobic bacteria, total psychrophilic bacteria, and Enterobacteriacae bacteria) of sea bass (Dicentrarchus labrax) fillets stored at 2±2^oC were investigated. The quality of sea bass fillets can be improved using nanoemulsions. This is a unique preservation technique given that purified oils were used without any other chemical compounds. The sensory analyses suggested that nanoemulsion treatment extended the shelf life of the sea bass from 8 days (the control) to 10 days. However, normal acceptability limits for bacterial counts were exceeded after 6 days for the control and 8 days for treated groups. The different commercial oil nanoemulsions noticeably retain the organoleptic quality parameters.Industrial relevanceNanoemulsions are regarded as self-preserving antimicrobials since the water present in them is effectively bound by its structure and access to the water by microorganisms is restricted. Nanoemulsions have adverse effects on the structure and function on bacteria by destabilising the organism's lipid envelope. Nanoemulsions can be used to extend the shelf life of fresh fish.     

Effects of ageing on stilbenes and biogenic amines in red grape winemaking with stem contact maceration

Stem contact maceration is a technique used in red winemaking for wines poor of phenolic constituents (tannins) in order to improve organoleptic characteristics and ensure color stability over time. This article investigates how the presence of different amounts of de‐stemmed bunches affects stilbenoids, known for their nutraceutical properties and biogenic amines (BAs), known for their adverse physiological and toxicological effects, at racking and after 24 months of storage in Primitivo wine. Stilbenes found in Primitivo were not influenced by the stems during maceration/fermentation. The ageing period resulted in isomerization phenomena of trans forms of piceid and resveratrol to the corresponding cis forms. The presence of stems during the winemaking did not induced the production or enhanced BAs content. Therefore, this enological practice does not represent a limit in terms of food safety and product quality.

Practical applications

Red wines poor in proanthocyanidins are subjected to color loss and decrease of organoleptic properties over time. Stem contact maceration is a technique used in red winemaking in order to enforce structure and stabilize color over time. Since food safety and product quality are of paramount importance, this study for the first time examines the presence of dangerous biogenic amines (BAs) and potent antioxidant stilbenoids throughout the production and aging of red wines produced with this technique. Results may benefit the winemaking industry and researchers who are striving to improve the processing and marketing of red wine.     

Zeta potential of tear samples: A tool to explore the effects of wear of contact lenses

PurposeThe aim was to develop a method to assess the electrostatic properties of human tear samples, and to evaluate their modifications induced by the wear of contact lenses (CLs).MethodThe barrier method was developed for the measurement of the isoelectric point (IEP) on relatively small quantities. The method was applied to compare three groups: tears (T_NW) of non-wearers, tears (T_{W_etaf}) of regular wearers of etafilcon A CLs, and tears (T_{W_omaf}) of regular wearers of omafilcon A CLs. Zeta potential (ζ) as a function of pH was measured by a Zetasizer Nano ZS90 (Malvern Instruments) on 40%-diluted samples, obtained by mixing 57 μL of tears of different subjects of the same group with 85 μL of HCl aqueous solution. IEP was deduced as the pH at which ζ is zero, i.e. the net electric charge on tear constituents being neutralized.ResultsWithin an error of about 0.05, IEPs were found to be 2.90 (T_NW), 2.80 (T_{W_omaf}), and 3.16 (T_{W_etaf}). On average, a lower H⁺ concentration is needed to neutralize the surface charge of the tear components of etafilcon A wearers, compared to both T_NW and T_{W_omaf}.ConclusionIEP measurements on tear samples of wearers of different types of CLs are proposed in order to enhance the knowledge on the modifications of the profile of charged species in tears. The T_{W_etaf} results, compared to those of the other groups, are compatible with an increase, due to the wear of etafilcon A CLs, of the relative concentration of high-IEP proteins.     

Inactivation of hepatitis A virus,poliovirus and a norovirus surrogate by high pressure processing

Hepatitis A virus (HAV), feline calicivirus (FCV, a surrogate for non-culturable norovirus), and poliovirus (PV), suspended in buffered cell culture media, were treated with pressures ranging from 200 to 600 MPa at ambient temperature for between 30 and 600 s. HAV was inactivated by > 1-log₁₀ tissue culture infectious dose 50% mL^− 1 (TCID₅₀ mL^− 1) and > 2-log₁₀ TCID₅₀ mL^− 1 after 600 s treatment with 300 and 400 MPa, respectively, and was undetectable (> 3.5-log₁₀ TCID₅₀ mL^− 1 reduction) within 300 s treatment with 500 MPa. FCV was inactivated by 3.6-log₁₀ TCID₅₀ mL^− 1 after 120 s treatment with 300 MPa, and was undetectable after 180 s treatment with 300 MPa. PV was the most resistant with little or no substantial reduction in titre after 300 s treatment with 600 MPa. The studies were designed to determine the efficacy of using high pressure to inactivate enteric viruses and generate inactivation data to assist in determining appropriate process criteria for safe shellfish production.Industrial relevanceThe high pressure treatment of raw oysters has proved commercially successful, due in part to a marked increase in the product’s shelf life, yet little alteration of its organoleptic properties. Illnesses from human enteric viruses such as hepatitis A virus and norovirus have traditionally been associated with shellfish consumption, and for this reason, studies have examined the stability of enteric viruses under high pressure. However, kinetic data on enteric virus stability under pressure is needed by processors to better understand the response of viruses throughout the entire treatment time. The kinetic data obtained in this study may be useful for processors wishing to alter high pressure processing conditions to ensure a high quality product in terms of organoleptic and microbiological properties.     

Process‐induced health‐promoting substances in foods

Abstract

Food processing not only provides an organoleptic quality to food, but also generates health‐promoting substances. Some of these substances, derived from popular food items like garlic, soybean, tea, and dairy products have been found to be beneficial in prevention and treatment of various ailments and diseases ranging from bites, headache and wounds, to heart problems, cancer, and oxidative stress. This review article summarizes the chemistry and health benefits of some processing derived food components.     

Sensory characteristics of wholegrain and bran-rich cereal foods – A review

BackgroundWholegrain foods are known to be health-beneficial but their sensory characteristics may be a limiting factor for consumption. The scientific literature of factors influencing sensory quality of wholegrain foods is rather scarce.Scope and approachMany cereals like rye, oats, barley and sorghum are actually used mainly as wholegrain, whereas for wheat the situation is the opposite. This review deals with factors that differentiate the sensory properties of wholegrain and bran-rich foods from those of refined cereal foods.Key findings and conclusionsWholegrain and bran contain flavour-active compounds, flavour precursors and resistant cell wall structures causing changes in flavour and texture during processing. In wholegrain foods, different chemical constituents contribute to bitterness. Increased knowledge on flavour formation has led to the possibility to not only measure but actually also design the flavour. Structure and texture are also important determinants underlying eating quality and stability of cereal foods. Hitherto established means of modulating sensory quality and thus improving acceptability of wholegrain foods are presented.     

Compositional changes in chlorophylls and carotenoids during the four flushes of tea in North East India

The quantitative changes of two pigments, chlorophylls a and b, and four major carotenoids, β-carotene, lutein, violaxanthine and neoxanthine, were investigated during four flushes of North East Indian plain teas from a deep skiffed area between April and October 1982. The tea flushes with different genetic properties were taken fromn from various Tocklai-released clones: TV-1 (Camellia sinensis (L.) O. Kuntze), TV-2 (C. assamica (Masters) Wight), TV-9 (C. assamica ‘Cambod’) and TV-17 (C. sinensis, hybrid). They showed marked changes in these pigment constituents throughout the plucking period, which affected the organoleptic property of the black tea produced.     

Quality comparison of carrot juices processed by high-pressure processing and high-temperature short-time processing

The effects of high-pressure processing (HPP) at 550 MPa for 6 min and of high-temperature short-time (HTST) processing at 110 °C for 8.6 s on carrot juice were evaluated. After HPP and HTST, the total plate count (TPC) was found to significantly decrease by 4.30 and 4.88 log₁₀ CFU/mL, respectively, and yeasts and molds (Y&M) were completely inactive. HPP-treated juice showed higher carotenoids, polyphenols, antioxidant capacity, viscosity, turbidity, and lower browning degrees (BDs) than HTST-treated juice, while HTST-treated juice contained higher polyacetylenes. HPP provided a more fresh-like quality and exhibited better aroma, taste, and overall acceptability. During 20 days of storage at 4 °C, both HPP- and HTST-treated juices were microbiologically safe (i.e., TPC < 2.4 log₁₀ CFU/mL, and Y&M were not detected), and their antioxidant capacities decreased linearly due to a decrease in carotenoid and polyphenol contents. The two juices did not precipitate any solids when their particle sizes decreased, and their viscosity increased; however, their organoleptic properties deteriorated as storage time increased.Industrial RelevanceThis study was intended to develop fresher and more stable carrot juice, which is not available on the market now. Acid blanching for a proper time was proved as an effective process in preventing juice serum isolation phenomenon of HPP juice, which is more likely to be accepted by consumers. HPP-treated juice had an advantage in nutritional and organoleptic properties than HTST-treated juice. This study provided a comprehensive technical support for novel application of HPP in carrot juice processing.     

Radiation preservation of foods of plant origin. III. Tropical fruits: bananas, mangoes, and papayas

The current status of research on the use of ionizing radiation for shelf life improvement and disinfestation of fresh tropical fruits like bananas, mangoes, and papayas are reviewed. The aspects covered are influence of maturity and physiological state of the fruits on delayed ripening and tolerance to radiation; varietal responses; changes in chemical constituents, volatiles, respiration, and ethylene evolution; biochemical mechanisms of delayed ripening and browning of irradiated fruits; and organoleptic quality. The efficacy of the combination of hot water dip and radiation treatments for control of postharvest fungal diseases are considered. The immediate potential of radiation as a quarantine treatment, in place of the currently used chemical fumigants, for disinfestation of fruit flies and mango seed weevil are discussed. Future prospects for irradiation of tropical fruits are discussed in the light of experience gained from studies conducted in different countries.     

Synergistic antimicrobial activity of two binary combinations of marjoram,lavender, and wild thyme essential oils

The combination of essential oils (EOs) is a novel alternative to improve their preservative effects and to reduce their organoleptic impact in food. In this context, this work aims to investigate the antibacterial combined effect of two EOs combinations through the calculation of the fractional inhibitory concentration index. The combinations tested consists of Lavandula dentata/Origanum majorana EOs and Thymus serpyllum/Origanum majorana EOs. Their chemical compositions were identified by CG/MS analyses. The main compounds of O. majorana EO were (-) - terpinene-4-ol and trans-4-thujanol. Those of L. dentata EO were β-pinene and 1,8-cineole, and those of T. serpyllum EO were p-cymene and γ-terpinene. Regarding the outcomes, results highlighted partial synergistic and additive interactions. Two combinations of marjoram and thyme EOs had antibacterial activities against S. aureus. The first one corresponded to the quarter of the minimum inhibitory concentration of marjoram and half that of thyme. The second one was the mix of half and quarter of the minimum inhibitory concentration of respectively marjoram and thyme EOs. This last combination also showed an antibacterial effect against E. coli. The quarter and the half of their minimum inhibitory concentration of marjoram and lavender combination, respectively, gave a partial synergy against both strains. Henceforth, these findings could be largely exploited in food preservation through the use of minimal doses of these plant products without affecting the antibacterial and the organoleptic properties in foods.     

Phytopharmacology of Acerola (Malpighia spp.) and its potential as functional food

BackgroundThe fruits of Malpighia glabra and M. emarginata (Family: Malpighiaceae) are commonly known as ‘Acerola cherry’ or ‘Barbados cherry’. Acerola fruits are well known for their high content of vitamin C, phenolic compounds, including benzoic acid derivatives, phenylpropanoids, flavonoids, anthocyanins, and carotenoids. In recent years, there is a growing interest in the role of Acerola as a nutraceutical or functional food with increasing market value. Extracts and bioactive compounds isolated from Acerola are studied for their various health promoting activities and biological activities such as antioxidant, antitumor, antihyperglycemic and skin protecting/skin whitening.Scope and approachThis article reviewed the scientific studies regarding the bioactive chemical constituents and the health beneficial effects of Acerola extracts and isolated compounds. These findings may help in future research concerning Acerola and Acerola based nutritional products.Key findings and conclusionsAcerola fruits can be considered as good candidates for the development of novel functional foods. However, detailed in vitro, in vivo and clinical studies, particularly mechanism-based studies are needed for the development of evidence-based functional food products in future.