Scanner-based color measurement in L * a * b * format with artificial neural networks (ANN)

A computerized inspection system (CIS) that uses a flat-bed scanner, a computer, and an algorithm and graphical user interface coded and designed in Matlab^® 7.0 was developed to determine food color based on CIE L ^* a ^* b ^*, a color format. The USA Federal Color Standard printouts (SP) comprised of 456 different colors were used to train and test the artificial neural network (ANN) integrated CIS. Strong correlations were found between the results estimated from ANN-integrated CIS and those obtained from spectrophotometer (R ², 0.991, 0.989, and 0.995 for L ^*, a ^*, and b ^*, respectively) for test images data set. Various food samples were also evaluated to test the performance of the CIS. A good agreement, R ², 0.958, 0.938, and 0.962 for L ^*, a ^*, and b ^*, respectively, was found between color measurement with CIS and a spectrophotometer. CIS with a mean error of 0.60% and 2.34% for test and various food samples, respectively, has an ability to imitate the results obtained from a spectrophotometer. CIS allows users to store the captured picture for further use and estimate the overall color or the color of selected region of the samples either heterogeneous in color or amorphous in shape.     

Thermal stability and long-chain fatty acid positional distribution on glycerol of argan oil

The primary aim of this study was to determine the oxidative stability of argan oils by using peroxides and conjugated diene hydroperoxides measurements as analytical indicators. Both food and cosmetic argan oils were investigated. Their oxidative stability was also determined by monitoring the relative changes of their fatty acid profiles by ¹H NMR. In addition, valuable information regarding minor components as well as the acyl positional distribution, were obtained for both grades by high field ¹H and ¹³C NMR, respectively. Given that the cosmetic and food grades have a similar profile and content of phenolic antioxidants, vitamers, and squalene, it appears that the ratio of fatty acid aliphatic to bisallylic CH₂ groups, much higher in argan oils than in other vegetable oils, is responsible for their higher thermal stability.     

Ultra-high-performance liquid chromatography–ion trap mass spectrometry characterisation of milk polar lipids from dairy cows fed different diets

Milk polar lipids are an important class of biologically active species for human health and for improving the physical functionality of food ingredients. Milk polar lipids from 144 multiparous Holstein–Friesian dairy cows fed different diets were analysed using ultra-high-performance liquid chromatography–ion trap mass spectrometry (UHPLC–MSⁿ). A complex profile of polar lipids, consisting of 7 species of phosphatidylinositol (PI), 12 species of phosphatidylethanolamine (PE), 18 species of phosphatidylcholine (PC) and 13 species of sphingomyelin (SM) were identified from the molecular ions and sequential MSⁿ fragmentation. Qualitative assessment of the data suggested that different cow diets influenced the relative amounts of a small number of species in the milk samples, e.g. PE 14:0/18:1, PE 18:0/18:1, PC 15:0/18:1, PC 18:0/18:1, SM d18:1/14:0, SM d18:1/15:0, SM d18:1/22:0 and SM d18:1/23:0.     

Variations in the transfer of radiocesium (Cs) and radiostrontium (Sr) from milk to cheese

This study aimed to compare the transfer of 2 manmade radionuclides, radiocesium (¹³⁷Cs) and radiostrontium (⁹⁰Sr), from cow milk to whey and cheese in 3 different types of French cheese production with rennet coagulation. Most of the ¹³⁷Cs was present in the aqueous phase and became concentrated in the whey. For ¹³⁷Cs transfer to whey, the processing factor (Pf; i.e., the ratio of the activity concentrations) ranged between 0.86 and 1.30 (n = 12). The food processing retention factor (Fr), calculated using the processing efficiency, ranged between 0.85 and 1.19 (n = 9). No statistical difference of Pf and Fr to whey is identified for ¹³⁷Cs and the cheese products. The Pf calculated for ⁹⁰Sr transfer to cheese ranged between 3.95 and 12.16, with significant differences depending on the type of cheese. In addition, a linear correlation is observed between ⁹⁰Sr Pf to cheese and the Ca level in the cheese (r² = 0.57). Thus, the Pf is enhanced in hard cheeses that are enriched in calcium. This is confirmed by nearly constant Fr values, ranging between 0.66 and 0.83.     

Antioxidant and Antimicrobial Activities of Allium roseum L. “Lazoul,” A Wild Edible Endemic Species in North Africa

Total polyphenolic contents (TPC), antioxidant and antibacterial activities of bulb, leaf and flower extracts of the North African endemic plant Allium roseum were studied using three different solvents. Flower and leaf TPCs were found significantly higher than that of bulb with the highest values in methanolic extracts reaching 736.65 ± 88.67 and 749.54 ± 129.15 mg catechol equivalent/100 g of dry material, respectively. The same trend was observed for antioxidant potentials using DPPH^. and ABTS^.+ scavenging methods. Moreover, the A. roseum phenolic extracts strongly inhibited the growth of a range of microorganisms. Multivariate analysis showed that the extraction solvent and the plant material significantly affected the quantity and bioactivity of the phenolics. Almost all extracts exhibited antioxidant and antibacterial activity; however, the highest values were found in the methanolic extracts of leaves and flowers. These results provide the basis for the use of this edible spontaneous species for functional food ingredients and/or supplements.     

Simultaneous detection of allergenic fish,cephalopods and shellfish in food by multiplex ligation-dependent probe amplification

People suffering from food allergy rely on correct food labelling as the ingestion of minimal amounts of the respective allergen can trigger severe allergenic reactions. Probes for the detection of DNA from allergenic fish, shellfish and cephalopod species in food using multiplex ligation-dependent probe amplification were developed. The specificity and the sensitivity of the detection system were investigated. The limit of detection was 20 mg kg^?1 for scallop, fish and bivalve species and 100 mg kg^?1 for cephalopod, gastropod and crustacean species using self-prepared sushi spiked with the analytes in different concentration levels. The analysis of 10 commercial food samples demonstrates the applicability of the developed method and its suitability for food quality control. Therefore, the method can be used to monitor the compliance with labelling rules regarding food allergens.     

N ϵ-(carboxymethyl)lysine: A Review on Analytical Methods,Formation, and Occurrence in Processed Food,and Health Impact

Foods are often heat processed and may contain advanced glycation end products (AGE). One of the most widely studied AGE is N ^?-(carboxymethyl)lysine (CML); nevertheless, knowledge on dietary CML is fragmentary. This study aimed to review current scientific knowledge on analytical methods to determine CML contents in food, chemical pathways of CML formation in food, occurrence of CML in food, and health implications of dietary exposure to CML. Chemical analyses of CML in food products are carried out by immunochemical assays and instrumental methods, but the former method may interfere with the food matrix. CML is formed in food through various chemical pathways, depending on food ingredients and processing conditions. The compound is present in many cooked foods, with relatively high concentrations in carbohydrate-rich foods and dairy products. Dietary CML is very likely to impair human health, but full cause-effect evidence is not available yet. More studies on metabolic effects and impact of food-derived CML on human health should be performed. Food production should be optimized to minimize CML concentrations, while maintaining acceptable microbiological safety and organoleptic properties of the final food product. To this end, more insights into effects of food composition and processing conditions on CML formation are necessary.     

Required barrier efficiency of internal bags against the migration from recycled paperboard packaging into food: a benchmark

The use of recycled paperboard and corrugated board for food packaging is in the interest of the sustainability of resources, but in most applications the food must be protected against contamination from these materials, such as by an internal bag with a functional barrier. Producers of packaging need a specification to find the most suitable and economical barrier for a given application, and the customer needs the confidence that a solution offered to him is adequate. An accurate determination of the barrier efficiency is not possible due to the large number of migrants, most of which have not been evaluated or not even identified. Hence the specification must be based on assumptions and verifiable by a simple test. The proposed benchmark presumes that the migration of all non-evaluated or even unknown substances in recycled paperboard will remain below 0.01 mg kg^–1 food, the conventional detection limit, if their transfer does not exceed 1% of the content in the paperboard. Some substances, such as mineral oil or fatty acids, will exceed the 0.01 mg kg^–1 limit, but they are known, evaluated and of no concern at the reduced migration. Since the critical substances must be assumed to be unknown, the criterion of the 1% migration is tested with three surrogate substances of similar volatility and covering a broad range of polarity. The cornerstones of the method are specified.     

Fatty acid composition of several wild microalgae and cyanobacteria, with a focus on eicosapentaenoic, docosahexaenoic and α-linolenic acids for eventual dietary uses

A total of 13 species of microalgae and 14 strains of cyanobacteria, collected directly in the Portuguese coast and lagoons, were characterized for their fatty acid contents, focusing on two with a market potential — i.e. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); and another already with alternative (yet somehow more expensive) natural sources — i.e. α-linolenic (ALA) acid. The purpose of this work was their eventual inclusion as additives in food or feed. ALA was the most abundant PUFA in Nannochloropsis sp. (0.616 ± 0.081 mg_FA.L_culture^{− 1}.d^{− 1}), and EPA in Phaeodactylum tricornutum (0.148 ± 0.013 mg_FA.L_culture^{− 1}.d^{− 1}); Pavlova lutheri was particularly rich in EPA (0.290 ± 0.005 mg_FA.L_culture^{− 1}.d^{− 1}) and DHA (0.140 ± 0.037 mg_FA.L_culture^{− 1}.d^{− 1}). Despite several previous reports on similar topics and encompassing some of our microalgal species, the wild nature of our strains accounts for the novelty of this work — in addition to the characterization of a few wild cyanobacteria. Eustigmatophyceae class was the best producer of ALA, while Prymnesiophyceae was the best for EPA and ALA. Nodularia harveyana exhibited the highest ALA level (0.611 ± 0.022 mg_FA.L_culture^{− 1}.d^{− 1}) and Gloeothece sp. was highest in EPA (0.030 ± 0.004 mg_FA.L_culture^{− 1}.d^{− 1}).     

Real-time PCR multiplex method for the quantification of Roundup Ready soybean in raw material and processed food

This paper describes a quantitative real-time multiplex PCR method optimised for the ABI PRISM^® 7700 Sequence Detection System (SDS) and TaqMan^® chemistry for Roundup Ready^® Soybean (RRS) in raw material and processed food. This method has the advantage of performing the amplification of the target taxon lectin gene and the genetically modified (GM) target sequence in the same test tube. The quantification is based on a calibration curve obtained with the DNA extracted from Certified Reference Material standards (CRM IRMM-410: R) in the range 0.1–5% RRS. The method was validated in-house by using CRMs and the applicability was verified on three mixtures of soybean flour at 1, 5, 10% of RRS respectively and on prepared baked products (biscuits and plum cakes). The statistical parameters of the method were found to be satisfactory both for soybean flour and baked products. In the process the absolute LOD and LOQ was 7.1 and 35.5 copy number respectively; the relative LOD and LOQ was 0.03 and 0.01% of RRS respectively.     

Characterisation and potential migration of silver nanoparticles from commercially available polymeric food contact materials

The potential for consumer exposure to nano-components in food contact materials (FCMs) is dependent on the migration of nanomaterials into food. Therefore, characterising the physico-chemical properties and potential for migration of constituents is an important step in assessing the safety of FCMs. A number of commercially available food storage products, purchased domestically within the United States and internationally, that claim to contain nanosilver were evaluated. The products were made of polyethylene, polypropylene and polyphenylene ether sulfone and all contained silver (0.001–36 mg kg^–1 of polymer). Silver migration was measured under various conditions, including using 3% acetic acid and water as food simulants. Low concentrations (sub-ppb levels) of silver were detected in the migration studies generally following a trend characterised by a surface desorption phenomenon, where the majority of the silver migration occurred in the first of three consecutive exposures. Silver nanoparticles were not detected in food simulants, suggesting that the silver migration may be due solely to ionic silver released into solution from oxidation of the silver nanoparticle surface. The absence of detectable silver nanoparticles was consistent with expectations from a physico-chemical view point. For the products tested, current USFDA guidance for evaluating migration from FCMs was applicable.     

Physical properties of a composite film containing sunflower seed meal protein and its application in packaging smoked duck meat

Sunflower seed meal protein (SP) films were prepared using various plasticizers, cross-linking agents, Cloisite Na⁺ or red algae, and their physical properties, such as tensile strength (TS), elongation at break (E), and water vapor permeability (WVP) were determined. The TS, E, and WVP of the SP film containing sucrose and fructose (2:1) as a plasticizer and cinnamaldehyde as a cross-linking agent were 3.05 MPa, 34.42%, and 2.25 × 10⁻⁹ g m/m² s Pa, respectively. The incorporation of Cloisite Na⁺ improved the physical properties of the SP film. The TS of the SP/Cloisite Na⁺ composite film containing 3% Cloisite Na⁺ increased by 2.19 MPa, and the WVP of the composite film decreased by 0.52 × 10⁻⁹ g m/m² s Pa compared to the SP film. The incorporation of red algae also improved the TS of the SP film. The TS of the SP composite film containing 1.2% red algae increased by 3.82 MPa compared to the SP film. In addition, an SP/red algae composite film containing grapefruit seed extract (GSE) was prepared and used in food packaging. After 12 days of storage, the population of Listeria monocytogenes inoculated on smoked duck meats packed with the SP/red algae composite film containing 1.2% GSE decreased by 1.31 log CFU/g compared to the control packaging. Therefore, these results suggest that SP composite films can be prepared by the addition of red algae to the SP film–forming solution and that the SP/red algae composite film containing GSE can be used as an antimicrobial food packaging material.     

Effects of plasticizers and nano-clay content on the physical properties of chicken feather protein composite films

To prepare chicken feather protein (CFP)/nano-clay composite films and to evaluate the effects of various plasticizers and nano-clay concentrations on the mechanical properties of the films, CFP composite films with various concentrations of Cloisite Na⁺ were prepared, and their physical properties such as tensile strength (TS), elongation at break (E), and water vapor permeability (WVP) were investigated. Optimal CFP films were formed with 5 g of CFP, 0.5 g of glycerol, and 1.5 g of sorbitol in 100 mL of film-forming solution; the TS, E, and WVP of the film were 4.74 MPa, 10.08%, and 3.11 × 10⁻⁹ g m/m² s Pa, respectively. After the nano-clay was incorporated into the CFP film-forming solution, scanning electron microscopy and X-ray diffraction studies were conducted to examine the structural characteristics of the CFP/nano-clay composite films. The incorporation of nano-clay improved the physical properties of the CFP films. The TS of the CFP/nano-clay composite film containing 7% Cloisite Na⁺ increased by 1.21 MPa, and the WVP of the composite film decreased by 1.15 × 10⁻⁹ g m/m² s Pa compared to the CFP film. Therefore, these results suggest that CFP composite films can be prepared with improved mechanical property by the addition of nano-clay and used as a food packaging material in the food industry.     

Interaction of copper ion with some food dyes.

The nature of the complexes formed by Cu²⁺ with some food dyes has been studied spectrophotometrically under varied conditions. The results indicated formation of 1:1 metal: dye species at pH 4.5 and of 2:1 metal: dye species at higher pH. The latter result is unexpected and surprising since in most cases azo dyes form 1:1 or 1:2 metal: dye species and no example of a metal complex having more than one metal atom per dye molecule has so far been reported. This curious observation has been rationalised in terms of a salt forming Cu²⁺ ion and a coordinated Cu²⁺ ion per dye molecule; tentative structures for these species have also been proposed. It is hoped this novel finding will stimulate further investigations into the metal-dye complexes.     

The I-SPy Insect Indicator: an effective trap for the detection of insect pests in empty stores and on flat surfaces in the cereal and food trades

A new trap, the CSL I-SPy Insect Indicator^®, has been assessed for monitoring adults of the principal crawling beetle pests of stored products in empty premises and on flat surfaces in grain stores and flour mills in the UK.The new trap was compared with the Igrox Insect Monitoring Peanut-free Bait Bag, the Storgard^® Flit-Trak M² trap and the Pantry Patrol™ trap in laboratory arenas using six beetle species of important pest status or which might be difficult to trap. The Pantry Patrol trap performed least well. The I-SPy Insect Indicator containing a carob lure was as good as, or better than, the Flit-Trak M² trap containing both food oil and pheromone lures in catching Oryzaephilus mercator (81.0% and 51.1%, respectively), Typhaea stercorea (87.4% and 31.1%), Tribolium confusum (44.6% and 37.5%) and Cryptolestes ferrugineus (45.1 and 53.8%). For the Bait Bag the catches for these species were 67.2%, 59.5%, 55.7% and 81.9% respectively. The I-SPy Insect Indicator containing a carob lure and the Flit-Trak food oil was as good as the Flit-Trak M² trap in catching Sitophilus granarius (92.9% and 99.2%, respectively) and Rhyzopertha dominica (50.6% and 51.5%).In limited trials in premises with unknown levels of infestation, the I-SPy Insect Indicator containing the carob lure and the Flit-Trak food oil was at least as good as the Flit-Trak M² trap in a grain store. In a flour mill, the I-SPy Insect Indicator with this combination caught more species, higher numbers of insects and was better at demonstrating the presence of infestation. The I-SPy Insect Indicator is also sturdy, reusable, easy to assemble and leaves the catch easy to identify. Importantly, it contains no food which might act as a source of re-infestation.     

Quantification of N-carboxymethyl-lysine in selected chocolate-flavoured drink mixes using high-performance liquid chromatography–linear ion trap tandem mass spectrometry

N^ε-carboxymethyl-lysine (CML) is considered to be an important marker of the Maillard reaction. In the present investigation a liquid chromatography coupled to ion trap tandem mass spectrometry has been developed for the analysis of CML and lysine in drink mixes. To ensure the best specificity of the method, porous graphitic carbon packing material was used for the chromatographic separation and two transition reactions were recorded per analyte. With the stable-isotope dilution technique employed in this method the recovery ranged from 100% to 111.4% for CML. All other performance characteristics tested were also satisfactory. The method was applied to the analysis of chocolate-flavoured drink mixes after sodium borohydride reduction and acid hydrolysis. In this food category, CML content varied from 8.1 to 131.9 μg/g powder or 95 to 3527 μg/g protein. Among the food items analysed by different laboratories chocolate-flavoured drink mixes appear to have one of the highest CML contents.     

Encapsulation of vitamin E in edible emulsions fabricated using a natural surfactant

Vitamin E is a fat-soluble vitamin widely used in pharmaceutical, supplement, food, and cosmetic preparations that must be encapsulated before it can be dispersed into aqueous-based products. The purpose of this study was to develop “all-natural” oil-in-water emulsions that could be used to incorporate vitamin E into functional food and beverage products. These emulsions were stabilized by a natural food-grade surfactant (Q-Naturale^®) isolated from the bark of the Quillaja saponaria Molina tree. The influence of oil phase composition (vitamin E to medium chain triglyceride (MCT) ratio), aqueous phase composition (glycerol to water ratio), and surfactant type (Q-Naturale^®versus Tween 80) on the size of the droplets produced by high pressure homogenization was examined. Small droplets could not be formed using only vitamin E acetate as the oil phase because of its very high viscosity, but they could be formed when ≥20% MCT was incorporated into the oil phase prior to homogenization. In the absence of glycerol, Q-Naturale^® was capable of forming emulsions containing relatively small droplets (d < 400 nm) from oil phases containing relatively high vitamin levels (60–80%). This droplet size could be decreased (d < 250 nm) by incorporating 50% glycerol in the aqueous phase prior to homogenization to increase its viscosity and decrease its interfacial tension. Tween 80 was more effective than Q-Naturale^® at producing small droplets when the oil phase contained low levels of vitamin E acetate (≤40%), but the opposite was true at higher vitamin levels. These results indicate that a natural surfactant (Q-Naturale^®) is effective at forming edible Vitamin E delivery systems that could be used in functional food and beverage applications.     

Acrylamide, 5-hydroxymethylfurfural and Nε-carboxymethyl-lysine in coffee substitutes and instant coffees

Sensitive analytical methods were developed and validated for the quantification of acrylamide, N^ε-carboxymethyl-lysine (CML) and 5-hydroxymethylfurfural (HMF) in 24 commercial coffee substitutes (CSs) and 12 instant coffees (ICs). Acrylamide levels varied widely from 200 to 4940 µg kg^–1 with higher levels in CSs. Only two out of 24 CSs had a level of acrylamide above the indicative value set for this food category by the European Commission (4000 µg kg^–1). None of the ICs tested in this study exceeded the indicative value set for this foodstuff (900 µg kg^–1). CML ranged from 0.17 to 47 mg kg^–1 and it increased in proportion to the protein content of the samples. The highest concentrations were found in IC partly due to the relatively high protein content of this food group. HMF was the most abundant neoformed compound (NFC) found in the tested commercial samples. It was found between 0.59 and 13 g kg^–1. Among other food categories IC and CS could appear to be major contributors to the exposure to NFCs if consumed on a daily basis. Further investigations are needed to elucidate the acrylamide formation during processing and to determine the daily intake level of frequent consumers of these products.     

Nitrate and nitrite content in organically cultivated vegetables

The nitrate and nitrite content of leaf vegetables (Swiss chard, sea beet, spinach and cabbage), “inflorescence” vegetables (cauliflower) and fruit vegetables (eggplant and vegetable marrow) grown with organic fertilizers have been determined by a modified cadmium–Griess method. Samples were purchased from organic food stores as well as collected directly from an organic farm in Madrid (Spain). Nitrate levels were much higher in the leaf vegetables (especially Swiss chard species; average over the different samples and species of 2778.6 ± 1474.7 mg kg^{? 1}) than in inflorescence or fruit products (mean values between 50.2 ± 52.6 and 183.9 ± 233.6 mg kg^{? 1}). Following Swiss chard species, spinach (1349.8 ± 1045.5 mg kg^{? 1}) showed the highest nitrate content, and nitrite was found above the limit of detection in some samples only (spinach, 4.6 ± 1.0 mg kg^{? 1}; sea beet, 4.2 ± 0.7 mg kg^{? 1} and Swiss chard, 1.2 ± 0.4 mg kg^{? 1}). Some vegetables (spinach, cabbage and eggplant) had lower nitrate content in the samples harvested in summer, showing the influence of climatic conditions on the nitrate levels in a plant. The samples taken directly from the organic farm, with the exception of eggplant, had higher or slightly higher average nitrate values than samples purchased in the organic food stores, ranging from 117 to 1077%.     

Influence of anthocyanins and derivative pigments from blueberry (Vaccinium myrtillus) extracts on MPP intestinal uptake: A structure–activity approach

The aim of the present study was to investigate the influence of an anthocyanin extract (extract I), and two other derivative extracts (extracts II and III), which are being developed aiming to be further applied in the food industry, on intestinal uptake of organic cations. For this purpose, the effect of these compounds on ³H-MPP⁺ uptake was evaluated in Caco-2 cells (an enterocyte-like cell line derived from a human colonic adenocarcinoma).