Degradation pathway of carnosic acid in methanol solution through isolation and structural identification of its degradation products

Carnosic acid is the primary rosemary-derived phenolic diterpenes with greatest antioxidant activity, but it is rather unstable in methanol solution. Understanding the degradation pathway of carnosic acid and the interaction between these phenolic compounds is important if they are to be utilized to a greatest effect. In this study, the HPLC analysis of an aged methanolic solution of carnosic acid revealed that carnosic acid was degraded, and several compounds were produced in the solution. From the time-course and quantitative analyses of the formation of the products and their structural analysis, a novel degradation pathway of carnosic acid in methanol solution is proposed. Carnosic acid can firstly decompose into carnosic acid quinone in methanol, which was the first time to be confirmed the existence of carnosic acid quinone. Carnosic acid quinone is the quinone intermediate of carnosic acid that can be reduced into carnosic acid or can be further converted into carnosol. Carnosol can further decompose to form epirosmanol, rosmanol, 7-methoxyrosmanol, and 7-methoxy-epirosmanol. The latter three compounds were identified as the final degradation products of carnosic acid in methanol because they appeared rather stable in the study.     

Screening of lactic acid bacteria for antimicrobial properties from mayonnaise-based products and raw materials

A collection of lactic acid bacteria isolated from both mayonnaise-based products and raw materials used to manufacture them was tested for antimicrobial activity. Out of 144 strains (97 lactobacilli, 23 lactococci and 24 enterococci) only three supernatants of Enterococcus spp. strains (EN3, EN14 and EN15) exhibited activity against lactobacilli and lactococci. The supernatant of the strain EN3 exclusively inhibited the growth of Bacillus cereus and Listeria monocytogenes. Enterococcus strains EN3, EN14 and EN15 produced thermostable bacteriocins, which had antibacterial activity.     

Transfollicular delivery of linoleic acid in human scalp skin: permeation study and microautoradiographic analysis

There are a large number of studies on the pharmacological activity of lineolic acid (LA) on the skin; however, very little work has been carried out to determine how LA targets the follicular structure. The aim of this study was to identify the preferred route of penetration of LA and to localize the molecule, using a microautoradiographic technique associated with a compartmental approach. In an in vitro test using topical application of 0.05 g of a formulation containing 1% of LA, 10% of the total recovery was found in the stratum corneum and dermis after 6 h. Microautoradiographic analysis of a 'virtual' slide showed most of the silver grains, i.e. LA, at the hair sheath, and none in the dermal compartment, confirming the diffusion of LA through a preferred transfollicular route. These results show, for the first time on human scalp skin, that the combination of compartmental analysis and microautoradiography points to a preferred transfollicular route of diffusion of topically applied LA. Thanks to its high-resolution, microautoradiography offers the advantage of providing detailed in situ information on the delivery of LA in the skin, including the cellular location of the molecule.     

Effect of heat treatment of film-forming solution on the properties of film from cuttlefish (Sepia pharaonis) skin gelatin

Effects of heat treatment at different temperatures (40–90 °C) of film-forming solution (FFS) containing 3% gelatin from cuttlefish (Sepia pharaonis) ventral skin and 25% glycerol (based on protein) on properties and molecular characteristics of resulting films were investigated. The film prepared from FFS heated at 60 and 70 °C showed the highest tensile strength (TS) with the highest melting transition temperature (T_max) (p < 0.05). Nevertheless, film from FFS heated at 90 °C had the highest elongation at break (EAB) with the highest glass transition temperature (T_g) (p < 0.05). With increasing heating temperatures, water vapor permeability (WVP) of films decreased (p < 0.05), but no differences in L*-value and transparency value were observed (p > 0.05). Based on FTIR spectra, the lower formation of hydrogen bonding was found in film prepared from FFS with heat treatment. Electrophoretic study revealed that degradation of gelatin was more pronounced in FFS and resulting film when heat treatment was conducted at temperature above 70 °C. Thus, heat treatment of FFS directly affected the properties of resulting films.     

Physicochemical characteristics and gelation properties of collagen superfine powder from swine skin: the effects of preheating treatment

Following different preheating treatments (60 °C for 20 min; 80 °C for 20 min; or 120 °C for 10 min, referred as T₁, T₂ and T₃), edible collagen superfine powder (CSP) from swine skin was prepared by superfine grinding method. The CSPs showed a preheating‐dependent decrease in the D₅₀, with different degrees of hydrolysis (9.51–31.05%). A significant effect of preheating on rheological properties of the CSP aqueous dispersions at pH 4–9 was observed, wherein T₂ had the biggest viscosity and water holding capacity. All the 5% CSP dispersions were transformed into stable cold‐set gels after heating at 50–90 °C for 20 min, with insignificant differences in strength. These attributes were consistent with microstructures of the CSP gels detected by scanning electron microscope.     

Studies on organoleptic properties of food products from fresh egg and egg powder through principal component analysis

The population which is below the poverty line is devoid of nutritious diet. Egg and milk are categorized as complete foods. The defensive organizations are situated in such remote places where fresh food material is not available. Keeping in view these problems, the study of organoleptic variables, viz., color, appearance, aroma, texture and taste in the food products of cake, omelet doughnut, coconut macaroon and mayonnaise from fresh egg and egg powder, was conducted. Principal component analysis was carried out. Organoleptic properties of doughnut prepared from egg powder were superior compared to fresh egg which had better sensory traits for coconut macaroon. The sensory traits like taste, texture and aroma were the most influential traits studied to pronouncing as a panel decision. It is proposed that fresh egg and egg powder should be preferred in the process of preparation of coconut macaroon and doughnut, respectively.     

Compositions,flavour and antiradical properties of products from subcritical water treatment of raw Isada krill

Comparative analysis of subcritical water (SCW) treatment and ambient pressure boiling one of raw Isada krill was performed for the nutritive, flavour and antiradical properties of krill extracts and residues as well as the molecular mass and odour intensity of the extract. SCW treatment was performed for 10 min in a batch‐type vessel in the temperature range of 100–240 °C, using a 1:1 weight ratio of raw krill to water. Higher protein and lipid contents were obtained by SCW treatment relative to boiling. The lipid content of the SCW extracts increased with increasing treatment temperature. Protein was the main component in these extracts, and the highest protein content was achieved by SCW treatment at 200 °C. High‐molecular‐mass species decomposed under SCW treatment at high temperatures with consequent generation of smaller molecules. The antiradical activity of the SCW extract, determined by DPPH and ABTS assays, increased with increasing treatment temperature. The krill extracts and residues exhibited shrimp‐like flavour, and the most desirable flavour was obtained by SCW treatment at 140 °C or 160 °C for 10 min. The treatment would be applicable for the production of seasonings from Isada krill.     

Safety assessment and antimicrobial properties of the lactic acid bacteria strains isolated from polish raw fermented meat products

Twenty-one strains of the genus Lactobacillus and the genus Pediococcus, isolated from Polish raw fermented meat products, were examined for the potential probiotic properties: resistance to simulated gastric and intestine conditions, safety assessment, and antimicrobial properties. Strains were resistant to gastric enzymes and low pH (3–6 log CFU/mL decrease) and intestinal enzymes and bile salts (1–3 log CFU/mL decrease). Most strains were resistant to gentamycin, streptomycin, vancomycin, tetracycline, ciprofloxacin, and kanamycin. Three of them (Lb. brevis BAL1, BAL10, and KL5) produced β-glucuronidase, which excludes them from qualifying as safe. Seven strains had the ability to produce bacteriocins or bacteriocin-like substances. Overall, strains Lb. brevis SCH6, Pd. pentosaceus BAL6, and KL14 revealed selected superior characteristics (resistance to the gastrointestinal conditions, safety assessment, and antimicrobial properties) as compared to the other LAB strains investigated, which made them a viable bioprotective culture that can be inoculated in raw fermented meat products as starter cultures.     

Squamometry: a tool to move from exaggerated to more and more realistic application conditions for comparing the skin compatibility of surfactant-based products

Squamometry consists of sampling the most superficial layers of the stratum corneum by means of a sticky tape firmly pressed onto the skin. Harvested cells are stained and the intensity of staining is related to the level of skin surface alterations caused by surfactant-based products. This method is extremely sensitive and the current study demonstrates that, thanks to squamometry, product mildness can now be compared without causing skin irritation due to exaggerated application conditions. In a 15 minute patch test, squamometry assessments ranked a series of surfactants as expected from their known irritation potential, without causing clinical signs of irritation. Similarly, the counter-irritant effect of amphoteric and nonionic surfactants on the irritation potential of anionic surfactants was evidenced. In a 30 minute patch test, shampoos were ranked by squamometry as they were in a classical Soap Chamber Test (48 hours of application). Finally, four hand dishwashing liquids were tested for one week by consumers according to a procedure similar to normal usage of the products, and were classified by squamometry as they were in a previous Soap Chamber Test. In conclusion, this study suggests that squamometry is able to predict the skin compatibility of surfactant-based products even after very short and realistic application times to volunteers' skin. Providing further validation, this technique could allow a move to test conditions much closer to the normal usage procedure of the products, to design test protocols much more respectful of panelists' skin condition, and to get information on product tolerance very quickly.     

Phenotypic identification and technological properties of lactic acid bacteria isolated from traditionally processed fish products of the Eastern Himalayas

Sukako maacha, gnuchi, sidra and sukuti are traditional smoked and sun-dried fish products of the Eastern Himalayan regions of Nepal and India. A total of 40 samples of sukako maacha (14), gnuchi (6), sidra (10) and sukuti (10) were collected and were analysed for microbial load. Population of lactic acid bacteria (LAB) as well as aerobic mesophilic counts ranged from 4.7-8.3 to 5.1-8.5 log cfu g(-1), respectively. A total of 189 strains of LAB were isolated from sukako maacha, gnuchi, sidra and sukuti samples, out of which 171 strains were cocci and 15 strains, were heterofermentative lactobacilli. LAB were identified on the basis of phenotypic characters including API system as Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Lactococcus plantarum, Leuconostoc mesenteroides, Enterococcus faecium, Enterococcus faecalis, Pediococcus pentosaceus and Weissella confusa. LAB strains produced a wide spectrum of enzymes. Some strains of LAB showed antagonistic properties against pathogenic strains. None of the strains produced biogenic amines in the method applied. This paper is the first report on the microbial composition, mostly lactic acid bacteria, of traditionally processed fish products of Eastern Himalayas.     

Use of octanoic acid as a postlethality treatment to reduce Listeria monocytogenes on ready-to-eat meat and poultry products

The antilisterial efficacy and organoleptic impact of an octanoic acid (OA)-based treatment for ready-to-eat (RTE) meat and poultry products were investigated. Whole-muscle and comminuted RTE products were inoculated with a five-strain mixture of Listeria monocytogenes. The OA treatments were applied to the surface of RTE products by dispensing a specific volume of solution directly into the final package prior to vacuum sealing. Once sealed, the vacuum-packaged RTE products containing OA were immersed in water heated to 93.3 degrees C (200 degrees F) for 2 s to effect adequate film shrinkage. Extending the time at which the packaged, treated RTE products were exposed to water heated to 93.3 degrees C was also evaluated with a commercial cascading shrink tunnel fitted with a modified drip pan. Once treated, RTE products were examined for survivor populations of L. monocytogenes after 24 h of storage at 5 degrees C. Sensory evaluation was conducted with a 60-member trained panel on 11 uninoculated, treated RTE products. The OA treatment of RTE products reduced L. monocytogenes numbers to between 0.85 log CFU per sample (oil-browned turkey) and 2.89 log CFU per sample (cured ham) when compared with controls. The antilisterial activity of OA was improved by increasing the duration of the heat shrink exposure. Specifically, reductions of L. monocytogenes ranged from 1.46 log CFU per sample (oil-browned turkey) to 3.34 log CFU per sample (cured ham). Results from the sensory evaluation demonstrated that 10 of the 11 treated RTE products were not perceived as different (P < or = 0.05) from the untreated controls. Panelists detected reduced (P < or = 0.05) smoke flavor intensity with treated mesquite turkey, although the treated product was viewed as acceptable. Results demonstrate the effectiveness of OA as a postlethality treatment meeting U.S. Food Safety and Inspection Service regulatory guidelines for RTE meat and poultry products with minimal impact on sensory quality.     

Effect of acid treatment on extraction yield and gel strength of gelatin from whiptail stingray (Dasyatis brevis) skin

Food Science and Biotechnology - Chemical properties of fish gelatins differ from those of conventional mammalian sources, representing an attractive technological alternative for the food...     

Physicochemical properties of gelatin gels from walleye pollock (Theragra chalcogramma) skin cross-linked by gallic acid and rutin

Gelatin gels were cross-linked by gallic acid and rutin. The gel strength, viscoelastic properties, thermal stability, swelling property, ultrastructure, X-ray diffraction patterns and FTIR spectra were determined to evaluate the physicochemical properties of the modified gels. The gel strength increased with increasing gallic acid concentration up to 20 mg/g dry gelatin, and then decreased at further elevated gallic acid concentration, while it continuously increased with increasing levels of rutin. Either cross-linking agent could enhance the elastic modulus (G′) and the viscous modulus (G″) of hydrogels, but the gelling and melting points didn’t show a notable improvement. Rutin boosted the thermal stability of xerogels, but decreased the equilibrium swelling ratio significantly, while as for gallic acid, there were no obvious effects on the thermal stability and equilibrium swelling ratio of xerogels. Scanning electron microscopy (SEM) was applied to observe the ultrastructure changes of the modified xerogels suggesting that gelatin xerogel at rutin concentration of 8 mg/g dry gelatin showed the highest cross-linking density. X-ray diffraction revealed that both gallic acid and rutin could enter the spacing of polypeptide chains of gelatin to reinforce the intermolecular interaction. And FTIR spectra verified that gallic acid and rutin molecules mainly interacted with skeletal C–N–C group and carboxyl group of gelatin molecules in the formation of gels. The results suggested that rutin was a better cross-linking agent for gelatin, and gels treated with rutin could be found with different physicochemical properties.     

Migration of additives from polymers into food simulants: numerical solution of a mathematical model taking into account food and polymer interactions

The principle of a computing program describing precisely the migration of additives from a polymer into a food simulant is presented. As six parameters are used to fit the simulant sorption and additive extraction kinetics, the parameters have been determined by independent experiments. Owing to the complicated coupling between the liquid and additive diffusion processes, migration kinetics cannot be obtained by a mathematical resolution of kinetic equations, but they must be calculated by numerical analysis. The method is applied to a UV absorber in polypropylene migrating into glyceryl tripelargonate, a pure triglyceride, of which behaviour and average molecular weight are similar to official fatty food simulants. Properly designed experiments validate the model used to fit the migration kinetics. The possibility of erasing any parameters is also discussed.     

Lactic acid bacteria isolated from raw and fermented pork products: Identification and characterization of catalase-producing Pediococcus pentosaceus

Food Science and Biotechnology - Lactic acid bacteria (LAB) from raw and fermented pork samples were screened for their inhibitory activity by an agar spot test in order to obtain a LAB strain with...     

Food hydrocolloids as additives to improve the mechanical and functional properties of fish products: A review

The restructuring process offers to fish processors the opportunity to obtain new products, taking advantage of both low-value fish species and remains from filleting and other processing operations. However, mechanical and functional properties of restructured products depend on the biochemical and physicochemical properties of muscle proteins, mainly myosin and actomyosin. In this regard, the biochemistry of fish muscle is different from that of mammals and birds. Therefore, fish products must be processed in a different way from red meat or poultry. The main fish products are surimi and restructured products. Fish products can be improved or modified by using hydrocolloids (carbohydrates and protein) as additives. In this review, the modern technology to obtain these products, the applications of hydrocolloids in fish products, and the implications of the increasing demand for healthy, low-salt fish products are discussed.     

Extraction and functional properties of gelatin from the skin of cuttlefish (Sepia officinalis) using smooth hound crude acid protease-aided process

The characteristics and functional properties of gelatin from skin cuttlefish (Sepia officinalis) were investigated and compared to those of halal bovine gelatin (HBG). The gelatin extraction efficiency was improved by an acid-swelling process in the presence of smooth hound crude acid protease extract (SHCAP). The yields of gelatins from cuttlefish skin after 48 h with acid and with crude acid protease (15 units/g alkaline-treated skin) were 2.21% and 7.84%, respectively. The gelatin from skin cuttlefish had high protein (91.35%) but low fat (0.28%) contents. Compared to HBG, the cuttlefish-skin gelatin (CSG) has different amino acids composition than halal bovine gelatin. CSG contained slightly low hydroxyproline and proline (180‰) than HBG (219‰), whereas the content of serine was higher (49‰ versus 29‰). The gel strength of the gelatin gel from CSG (181 g) was lower than that of HBG (259 g) (p < 0.05) possibly due to lower hydroxyproline content. Cuttlefish-skin gelatin exhibited a similar emulsifying activity but greater emulsifying and foam stability than the halal bovine gelatin (p < 0.05). Foam formation ability, foam stability and water-holding capacity of CSG were slightly lower than those of the HBG, but fat-binding capacity was higher in the cuttlefish gelatin.     

Physical properties of acid milk gels: Acidification rate significantly interacts with cross-linking and heat treatment of milk

Rheological properties and microstructure of acid milk gels largely depend on the pre-treatment of the milk, including heating and enzymatic modification of the gel-forming proteins. It was the aim of our study to investigate the impact of the acidification rate on gels which were produced from milk reconstituted from powder containing casein cross-linked by microbial transglutaminase (mTGase), and on gels which were produced from cross-linked raw milk. 3–7% Glucono-δ-lactone (GDL) was used as acidulant. Gel stiffness was determined by dynamic small-deformation rheometry and penetration experiments, and forced syneresis and gel permeability served as indicators for gel microstructure.     

A double-blind and controlled study on the influence of the vehicle on the skin susceptibility to stinging from lactic acid

Synopsis For patients with skin diseases, the process of treating the skin with topical medications adds to the burden of having the disease. Inconvenient skin reactions can make the treatment troublesome and lower the compliance. Moreover, epidemiological surveys indicate that 50% or more of female consumers believe they have sensitive skin. In the present study, the influence of the vehicle on the adverse skin reaction to lactic acid was judged by the test subjects after application of the test formulations to the facial skin. The results showed a water-in-oil (w/o) emulsion to induce less stinging than an ordinary oil-in-water (o/w) emulsion. Increasing the mineral oil content in the o/w emulsion from 10% to 50% tended (P = 0.077) to decrease the stinging potential of the formulation. An o/w emulsion free from lactic acid but with pH adjusted to 3 using hydrochloric acid induced significantly less stinging than the corresponding lactic acid formulation at pH 3. In conclusion, the present study gives new insights into the influence of vehicle on the stinging capacity of lactic acid, which may be related to its possible penetration via appendages. Hence, encapsulation of the stinging substances in the inner water phase of an emulsion may be a possible option to reduce adverse skin reactions and to increase compliance to water-soluble substances.     

Combined enzymatic and colorimetric method for determining the uronic acid and methylester content of pectin: Application to tomato products

A simple procedure for determining the galacturonic acid and methanol contents of soluble and insoluble pectins, relying on enzymatic pectin hydrolysis and colorimetric quantification, is described. Pectin samples are incubated with a commercial pectinase preparation, Viscozyme, then the galacturonic acid content of the hydrolyzed pectin is quantified colorimetrically using a modification of the Cu reduction procedure originally described by Avigad and Milner. This modification, substituting the commonly used Folin–Ciocalteau reagent for the arsenic containing Nelson reagent, gives a response that is linear, sensitive, and selective for uronic acids over neutral sugars. This method also avoids the use of concentrated acids needed for the commonly used m-phenylphenol method. Methanol, released by the action of the pectin methylesterase found in the Viscozyme, is quantified using alcohol oxidase and Purpald. This combined enzymatic and colorimetric procedure correctly determined the galacturonic acid and methanol content of purified, soluble citrus pectin. Application of the procedure to water insoluble pectins was evaluated with water insoluble material from apples and oranges. In both cases good agreement was obtained between this method and commonly used methods based on chemical pectin hydrolysis. Good agreement between these procedures was also found in the analysis of both soluble and insoluble pectins from several tomato products.