Pyrraline formation prevented by sodium chloride encapsulated by binary blends of different starches and gum Arabic in aqueous model systems and cookies

Pyrraline is a common advanced glycation end product that is closely associated with various chronic diseases and frequently found in commonly consumed foods. In this study, pyrraline formation prevented by NaCl encapsulated by binary blends of different starches and gum arabic was investigated. The results show that in aqueous model systems with encapsulated NaCl addition, the reduction in pyrraline varied from 5.4% to 26.7%, with simultaneous decreases in the 3-deoxyglucosone (3-DG) concentration, which varied from 13.1% to 41.4%. In cookies with encapsulated NaCl addition, decreases in pyrraline varied from 10.2% to 31.6% accompanied by simultaneous decreases in 3-DG, which varied from 14.2% to 39.4%. However, NaCl encapsulation had no impact on the browning extent in aqueous model systems and on the basic sensory indicators of the manufactured cookies, including colour and salty taste.     

Influence of the microencapsulation on the quality parameters and shelf-life of extra-virgin olive oil encapsulated in the presence of BHT and different capsule wall components

The main goal of this study was to assess the influence of the microencapsulation on the oil chemical composition and its oxidative stability. Factors such as microcapsule wall constituents and the addition of the antioxidant butylhydroxytoluene (BHT) were investigated in order to establish the most appropriate conditions to ensure no alteration of the extra-virgin olive oil chemical characteristics. The microencapsulation effectiveness was determined in base of process yield and the microencapsulation efficiency. Highest encapsulation yields were achieved when maltodextrin, carboxymethylcellulose (99.79 ± 0.51%) and lecithin were used as encapsulation agents and the ratio of oil-wall material was 1:1.5. Stability studies were achieved by placing encapsulated oil and un-encapsulated oil in heated chambers at 30 °C during 4 months. Oxidative stability and oil quality studies were periodically assessed. It was concluded that the presence of protein constituents in the microcapsule wall material extended the shelf-life of the microencapsulated olive oil (protein-based model microencapsulated oil was unalterable for 9 to 11 months). For this later model, the addition of antioxidant additives did not significantly increase the oil stability.     

Rheological behavior and stability of d-limonene emulsions made by a novel hydrocolloid (Angum gum) compared with Arabic gum

Our goal was to evaluate emulsion stability, droplet size analysis and rheological behavior of the emulsions prepared by a native biopolymer namely Angum gum (An) compared with Arabic gum (Ar) stabilized emulsions. After gum extraction, gum dispersions with maltodextrin were prepared in water (in 1-5% concentrations) and emulsified with 5% and 10% d-limonene using high pressure homogenization. Statistical analysis revealed a significant influence of gum type and gum concentration on emulsion stability at α = 0.05. Flavor level was not important statistically in emulsion stability but it was the only factor with a significant influence (P < 0.05) on surface tension of the emulsions. The results showed that Angum gum was superior to Arabic gum in stabilizing emulsions during storage. Also, rheological data revealed that Angum gum-emulsions’ behavior was following the Herschel-Bulkley model with higher viscosities compared to Arabic gum emulsions, which could be the main reason of higher emulsion stabilities with this novel hydrocolloid.     

Use of an edible coating containing galbanum gum and cumin essential oil for quality preservation in sweet cherries

Nowadays, the use of natural compounds is considered as an effective strategy for maintaining the quality and heath promoting capacity of fresh products. Changes in quality parameters, main phenolics and antioxidants of sweet cherries in response to coating with a novel bioactive edible coating were studied. Fruit were treated with different concentrations of galbanum gum (GG), cumin essential oil (CEO) and CaCl₂ (CA) and stored at 2 ± 1°C with 90–95% RH for 30 days plus 1 day at ambient condition, and were subjected to quality analysis. All phenolic constituents and antioxidants of fruit juice were substantially decreased during storage in control fruit and a bioactive coating containing 1 or 2% GG + 100 or 200 µL L⁻¹ CEO + 1% CA maintained main fruit phytochemicals including phenolics, phenolic acids, flavonols, anti-stress and antioxidant enzymes activities. The coating significantly (P ≤ 0.01) enhanced fruit total antioxidant activity, flavonoids and ferulic acid contents. The results showed that it is possible to enhance the sweet cherry fruit health-promoting phytochemicals and shelf life by the use of a natural edible coating containing GG and CEO.     

Chemometrics coupled with ultraviolet spectroscopy: a tool for the analysis of variety,adulteration, quality and ageing of apple juices

This study demonstrates the use of UV spectroscopy (UV) in combination with chemometrics as a simple and feasible approach for analysis of variety, adulteration, quality and ageing of apple juice. The results show that PCA‐UV is adequate to differentiate apple juice varieties and adulteration. The percentage of the adulterant can be detected by PLSR‐UV with RMSE < 0.7783% and R² > 0.9980. For the evaluation of juice quality, PLSR‐UV (RMSE = 0.2555–2.3448; R² = 0.7276–0.9816) is recommended for the prediction of soluble solids, ascorbic acid, total flavonoids, total sugar and reducing sugar, whilst PCR‐UV (RMSE = 0.0000–2.7426; R² = 0.7073–1.0000) is adequate for the prediction of pH and antioxidant activity. In addition, PLSR‐UV may be used to predict the storage time with RMSE = 0.4681 day and R² = 0.9832. Therefore, UV coupled with chemometrics has potential to be developed as a portable tool for the detection of variety, adulteration, quality and ageing of not only apple juices, but also other fruit and vegetable juices.     

HGC和UV-HGC测定植物油中溶剂残留量的不确定度评定

通过顶空气相色谱法和超声振荡-顶空气相色谱法测定植物油中六号溶剂残留量,对测定过程中的不确定度来源进行分析,依据JJF 1059.1—2012《测量不确定度评定与表示》和CNAS-GL06《化学分析中不确定度的评估指南》中有关规定,建立数学模型,并对各分量进行量化,评定结果表明:影响检测结果不确定度的关键控制点为样品的前处理和标准曲线。     

Application of a model using the phenomenological approach for prediction of growth and xanthan gum production with sugar cane broth in a batch process

Production of xanthan gum was studied and modelled using unstructured kinetic models composed of three differential equations, which considered the microbial biomass, carbon source, and xanthan concentration. The fermentation process, using Xanthomonas campestris pv. campestris NRRL B-1459, was conducted under controlled conditions with diluted sugar cane broth at different initial sucrose concentrations (15.0, 25.0, and 35.0 g L⁻¹). Unstructured kinetic models proposed in the literature for this system were reviewed and applied. These models were tested against the experimental results, calculating the parameters by nonlinear regression. The kinetic models used in this study provided estimations of microbial growth, substrate consumption, and product formation, and, therefore, these parameters were quantified in the fermentation experiments. Higher yield of xanthan per amount of sucrose (0.58 g g⁻¹) and productivity (0.63 g L⁻¹ h⁻¹) were obtained using initial sucrose concentrations of 25.0 and 35.0 g L⁻¹, respectively. The models were used to predict the kinetic parameters for a medium containing an intermediate and a larger initial sucrose concentration (27.0 and 40.0 g L⁻¹). When tested experimentally, the measured fermentation parameters were in close agreement with the values predicted by the model that presented the best adjustment, demonstrating its validity.     

Recent developments in the application of seaweeds or seaweed extracts as a means for enhancing the safety and quality attributes of foods

The production of rancid flavors and odors due to oxidative stress in foods can lead to a reduction in the sensory attributes, nutritional quality and food safety. Due to consumer demands, interest has been generated in searching plant products for natural “green” additives. Extracts from macroalgae or seaweeds are rich in polyphenolic compounds which have well documented antioxidant properties. They also have antimicrobial activities against major food spoilage and food pathogenic micro-organisms. Thus, possibility of seaweeds being added to foods as a source of antioxidant and antimicrobial is the main focus of this communication. In addition, seaweeds are also rich in dietary minerals specially sodium, potassium, iodine and fibers. Another potential area where the use of seaweed is gaining importance is regarding their addition for improving the textural properties of food products which is also extensively reviewed in this paper.

Industrial relevance

The trend towards the use of “natural green” plant extracts in various food and beverages in the food industry is gaining momentum. Seaweed, being a rich source of structurally diverse bioactive compounds with valuable nutraceutical properties, can be used as an ingredient to supplement food with functional compounds. Interest in the application of such compounds as natural antioxidants, antimicrobials or texturing agents in different food products is greater than ever. The addition of seaweeds or their extracts to food products will reduce the utilization of chemical preservatives, which will fulfill the industry as well as consumer demands for “green” products. In addition, the current status and the future projections in the functional effects of seaweeds as a means to improve the fiber content and reduce the salt content of food products, which will be of significant importance to the meat industry, is also discussed.     

Rocket immunoelectrophoresis (RIE) for determination of potentially allergenic peanut proteins in processed foods as a simple means for quality assurance and food safety

 Peanuts are one of the most allergenic foods known. The presence of hidden allergens in processed food for reasons of mislabelling or cross-contamination expose allergic individuals to unpredictable risks, especially since highly sensitized subjects may experience severe anaphylactic reactions. The protection of consumers requires specific and sensitive methods for the detection of trace amounts of potentially allergenic peanut components. A rocket immunoelectrophoresis (RIE) procedure was developed allowing the detection of even spurious contaminations with peanut protein. For precipitation of peanut protein a commercially available antiserum was used. By amplifying precipitates with a secondary immunodetection step, 20 ng/ml peanut protein in chocolate extract, equivalent to 0.0002% peanut in chocolate, could still be detected. Model chocolate spiked with various amounts of peanut was investigated down to 0.001% peanut (10 ppm), the limit of quantitative determination. The method was optimized for detection of peanut in chocolate samples. Non-chocolate samples had to be standardized with a chocolate matrix prior to analysis in order to obtain a uniform response. Cross-reactivities with other food proteins did not occur. The method showed high recoveries of 85–101% for chocolate samples down to 10 ppm peanut and good reproducibility with coefficients of variation of ≤ 5 % for samples of ≥ 15 ppm peanut protein. The applicability of this method in the detection of peanut protein in various food commodities was demonstrated: two unlabelled products and two products which did not have peanut listed as an ingredient were identified as containing peanut protein. In all cases where peanut was listed, peanut protein could be determined. The results of RIE were always confirmed by those of a new cell-mediator-release assay that is based on a rat basophil leukaemia (RBL) cell-line (RBL-2H3), cells that are a functional equivalent to mucosal mast cells. Measuring the release of β-hexosaminidase resulting from cross-linking of basophil-bound peanut-specific immunoglobulin E, the assay mimics a main event of the allergic type-I reaction. The cell assay was adapted for food matrices and peanut could be detected down to 0.01% which additionally demonstrated in vitro that even trace amounts of peanut protein could elicit allergic reactions. Received: 28 May 1997 / Revised version: 11 July 1997     

Rocket immunoelectrophoresis (RIE) for determination of potentially allergenic peanut proteins in processed foods as a simple means for quality assurance and food safety

 Peanuts are one of the most allergenic foods known. The presence of hidden allergens in processed food for reasons of mislabelling or cross-contamination expose allergic individuals to unpredictable risks, especially since highly sensitized subjects may experience severe anaphylactic reactions. The protection of consumers requires specific and sensitive methods for the detection of trace amounts of potentially allergenic peanut components. A rocket immunoelectrophoresis (RIE) procedure was developed allowing the detection of even spurious contaminations with peanut protein. For precipitation of peanut protein a commercially available antiserum was used. By amplifying precipitates with a secondary immunodetection step, 20 ng/ml peanut protein in chocolate extract, equivalent to 0.0002% peanut in chocolate, could still be detected. Model chocolate spiked with various amounts of peanut was investigated down to 0.001% peanut (10 ppm), the limit of quantitative determination. The method was optimized for detection of peanut in chocolate samples. Non-chocolate samples had to be standardized with a chocolate matrix prior to analysis in order to obtain a uniform response. Cross-reactivities with other food proteins did not occur. The method showed high recoveries of 85–101% for chocolate samples down to 10 ppm peanut and good reproducibility with coefficients of variation of ≤ 5 % for samples of ≥ 15 ppm peanut protein. The applicability of this method in the detection of peanut protein in various food commodities was demonstrated: two unlabelled products and two products which did not have peanut listed as an ingredient were identified as containing peanut protein. In all cases where peanut was listed, peanut protein could be determined. The results of RIE were always confirmed by those of a new cell-mediator-release assay that is based on a rat basophil leukaemia (RBL) cell-line (RBL-2H3), cells that are a functional equivalent to mucosal mast cells. Measuring the release of β-hexosaminidase resulting from cross-linking of basophil-bound peanut-specific immunoglobulin E, the assay mimics a main event of the allergic type-I reaction. The cell assay was adapted for food matrices and peanut could be detected down to 0.01% which additionally demonstrated in vitro that even trace amounts of peanut protein could elicit allergic reactions. Received: 28 May 1997 / Revised version: 11 July 1997     

Suitability of three commercially produced pig breeds in Germany for a meat quality program with emphasis on drip loss and eating quality

This study aimed at characterising 606 crossbred pigs of three commercially available breed types in terms of their carcass and meat quality. Breed G and H were German Large White (LW) × German Landrace (LR) sows sired with Pietrain (PI) boars, i.e. PI × (LW × LR). Breed S was 25% Duroc (DU), i.e. PI × (DU × LR). Most of the parameters were affected by breed and/or date of slaughter. The meat of crossbred pigs with 25% Duroc proportion appeared most favourable because of higher intramuscular fat content, lower drip loss and higher sensory liking scores. Conductivity is closely related to drip loss while the data suggests that the relationship is dependent on breed and carcass weight. The application of conductivity and lean meat yield thresholds to select carcasses with uniform and superior meat quality effectively decreased drip loss and increased intramuscular fat content as well as sensory liking scores. The variation of meat quality traits remains high, though.     

Classification of wooden breast myopathy in chicken pectoralis major by a standardised method and association with conventional quality assessments

Wooden breast (WB) abnormalities of broilers compromise the quality of fresh and processed meat. Yet, no standardised classification method for evaluating WB currently exists. We here provide a novel classification method to determine the severity of WB by palpation. Data were evaluated by one‐way anova . The classification method proved robust and reliable to classify broiler filets into three distinct categories (no, moderate and severe WB). This was supported by histological findings, demonstrating less muscle tissue in WB‐affected samples. Moreover, moisture content, resistance to compression, mobile water fraction, drip loss and cooking loss, as well as intramuscular and surface pH also increased with WB. Using the classification method, we demonstrated that severe WB increased the diversity of the endogenous microflora and promoted growth of Enterobacteriaceae. In conclusion, the presented classification method correlates with known meat quality traits and will be a valuable tool for future studies on WB.     

Use of global sensitivity analysis in quantitative microbial risk assessment: application to the evaluation of a biological time temperature integrator as a quality and safety indicator for cold smoked salmon

The aim of this study was to apply a global sensitivity analysis (SA) method in model simplification and to evaluate (eO)^®, a biological Time Temperature Integrator (TTI) as a quality and safety indicator for cold smoked salmon (CSS). Models were thus developed to predict the evolutions of Listeria monocytogenes and the indigenous food flora in CSS and to predict TTIs endpoint. A global SA was then applied on the three models to identify the less important factors and simplify the models accordingly. Results showed that the subset of the most important factors of the three models was mainly composed of the durations and temperatures of two chill chain links, out of the control of the manufacturers: the domestic refrigerator and the retail/cabinet links. Then, the simplified versions of the three models were run with 10⁴ time temperature profiles representing the variability associated to the microbial behavior, to the TTIs evolution and to the French chill chain characteristics. The results were used to assess the distributions of the microbial contaminations obtained at the TTI endpoint and at the end of the simulated profiles and proved that, in the case of poor storage conditions, the TTI use could reduce the number of unacceptable foods by 50%.     

Characterisation of vitamin B12 immunoaffinity columns and method development for determination of vitamin B12 in a range of foods,juices and pharmaceutical products using immunoaffinity clean-up and high performance liquid chromatography with UV detection

New rapid and simpler procedures, using immunoaffinity columns, have been developed for the determination of vitamin B12 in a range of samples including three different US National Institute of Standard and Technology (NIST) Reference Materials, infant formula, powdered energy drinks and bars, wheat breakfast cereal, carbonated soft drinks, fruit juices and vitamin B12 tablets. The procedures involved extraction of vitamin B12 using water or sodium acetate buffer and enzyme digestion (using pepsin or α-amylase, or both) if necessary. The extract was clarified and passed through “EASI-EXTRACT® Vitamin B12”, an immunoaffinity column containing monoclonal antibody with high affinity and specificity to vitamin B12. Subsequently, the vitamin B12 immunoaffinity column was washed with 10 ml water and the vitamin B12 was released from the column with 3 ml methanol. Following evaporation, the samples were reconstituted in mobile phase and analysed by HPLC–UV at 361 nm on an ACE 3AQ analytical column using a gradient elution consisting of 0.025% trifluoroacetic acid in water and acetonitrile. Analysis of three types of NIST Standard Reference Materials in triplicate demonstrated the results of the immunoaffinity column method were comparable to microbiological assay results. Method repeatability was determined for all samples analysed and ranged between 0.8 and 10%, demonstrating the method was repeatable with complex matrices (NIST 2383) containing low levels of vitamin B12 (0.44 μg per 100 g), as well as simpler matrices, such as vitamin tablets containing high levels (2000 μg per 0.849 g) of vitamin B12.     

超高效液相色谱大体积流通池荧光法检测花生油中黄曲霉毒素B1的不确定度评定

目的 评定超高效液相色谱大体积流通池荧光法测定花生油中黄曲霉毒素B₁含量的不确定度。方法 依据GB 5009.22-2016《食品安全国家标准 食品中黄曲霉毒素B族和G族的测定》第三法无衍生器法测定花生油中黄曲霉毒素B1(AFTB₁),根据JJF1059.1-2012《测量不确定度评定与表示》建立超高效液相色谱大体积流通池测定花生油中AFTB₁含量的数学模型,对各个不确定度分量进行评定和分析。结果 在95%置信区间下,当花生油中AFTB₁含量为1.1815μg/kg时,其扩展不确定度为0.2217μg/kg,k=2。结论 检测结果的不确定度主要受标准曲线拟合、样品回收率、标准溶液配制、重复性测定影响。     

Development of a flavour fingerprint by GC‐MS and GC‐O combined with chemometric methods for the quality control of Korla pear (Pyrus serotina Reld)

Based on solid‐phase micro‐extraction/gas chromatography‐mass spectrometry (SPME/GC‐MS) and gas chromatography‐olfactometry (GC‐O), a new method was described for the first time to establish flavour fingerprint for the quality control of Korla pear. Twenty‐three batches of Korla pear collected from different regions in Xinjiang, China were analysed via GC‐MS, among which 21 were selected to establish the fingerprint. The results of the analysis were combined with GC‐O assessment to obtain 26 common odour‐active compounds as the characteristics of the Korla pear flavour fingerprint. The method for flavour fingerprint analysis was then validated on the basis of the relative retention time and relative peak area of the common peaks, sample stability and similarity analysis. The similarities in the 21 Korla pear samples were more than 0.80, thereby indicating that the samples from different batches were consistent to a particular extent. The chemometrics method (principal component analysis, PCA) was performed to develop a flavour fingerprint that is suitable for identifying and differentiating Korla pears and can be used for quality control.     

A developed pre-column derivatization method for the determination of free fatty acids in edible oils by reversed-phase HPLC with fluorescence detection and its application to Lycium barbarum seed oil

Free fatty acids (FFAs) in edible oils are one of the most frequently determined quality indices during production, storage, and marketing. In this study, a simple, stable and sensitive method for the simultaneous determination of saturated and unsaturated FFAs from edible oils using 2-(11H-benzo[a]carbazol-11-yl)-ethyl-4-methylbenzenesulphonate (BCETS) as labelling reagent with fluorescence detection has been established. FFAs are derivatized by BCETS and separated on a reversed-phase Eclipse XDB-C₈ column with a gradient elution. The results indicated that all FFAs were found to be given an excellent linear response with correlation coefficients of >0.9994. The detection limits at a signal-to-noise ratio of 3 were in the range of 0.22–1.06 ng/mL. When applied to Lycium barbarum seed oils, the developed method showed good reproducibility. The effect of extraction methods including supercritical CO₂ and organic solvent extraction on the FFAs composition has also been investigated. Meanwhile, this method exhibits powerful potential for the trace analysis of short- and long-chain free fatty acids from edible oils, foodstuff and other complex samples.