Commercial Food Products Research Articles

Diversity and characterization of spoilage-associated psychrotrophs in food in cold chain

In this work, psychrotrophs known to cause food spoilage were isolated from commercial food products. Further, temperature sensitivities and volatile organic compounds of the representative strains were characterized to evaluate the population heterogeneity. A total of 490 isolates belonging to 38 genera of 20 families were identified from 30 psychrotroph-positive samples, among which Gram-negative bacteria occurred frequently. The genus Pseudomonas exhibited a clear predominance, especially Pseudomonas fragi, followed by Psychrobacter, Brochothrix, Serratia, and Stenotrophomonas, with the dominant bacteria varying with origin. Aquatic products related to Hafnia and quick-frozen food corresponding to Stenotrophomonas, as well as livestock products were shown to be good ecological niches for growth of psychrotrophs. The genus Pantoea was shown to have an intimate relationship with fruits. While in bean, cereal grain and dairy products, only Pseudomonas was present. The fits of the growth curves demonstrated good adaptability and tolerance of the tested strains under 4 °C, and multifarious growth also reflected intra-species differences and phenotypic diversity. Various kinds of esters, aromatic compounds, alcohols, and ketones were frequently detected by GC–MS. High alcohols were seen in Psychrobacter, but hydrocarbons and ethers were more often found in Pseudomonas. In particular, since high amounts of isophorone were only discovered in bacteria samples, it is speculated to be the characteristic substance of psychrotrophs.

High amylose cornstarch preloads stabilized postprandial blood glucose but failed to reduce appetite or food intake in healthy women

High fiber diets promote satiety and sustain normal blood glucose by delaying digestion and slowing glucose absorption, but their longer-term impact on body weight loss is thought to be due primarily to their lower energy density. Starches that are digested slowly in the small intestine, resistant starches (RS), contribute to a diet's fiber load. The worldwide epidemic of obesity has supported the incorporation of RS in commercial food products to curtail body weight gain. AimThe present study explored whether consumption of a beverage containing RS, from high amylose cornstarch (Amylose), will lead to higher satiety and lower energy intake (EI). MethodsPreload beverages containing 75 gm Amylose, Glucose, or a Glucose-Amylose mixture were administered to young healthy females after an overnight fast and blood glucose and appetite measurements were taken at 0, 15, 30, 45, 60, 90, 120, 180 and 240 min. Calorie intake was assessed at a pizza meal at 2 h (Experiment 1) or 4 h (Experiment 2). ResultsThe glycemic responses were lower with Amylose: Glucose > Glucose-Amylose > Amylose = water Control (p < 0.0001). Appetite was not affected by the treatments (p > 0.05). EI was lower only after Glucose at 2 h, but unaffected by treatment after 4 h. ConclusionAs high amylose cornstarch improves postprandial blood glucose response but has no effect on satiety and EI, a more careful analysis of its benefits for body weight loss is needed. The research was funded by the Research Office of Kuwait University, Grant # FF01/16. Study registrationTCTR20180815005.

Development of a fast real-time PCR assay based on TaqMan probe for identification of edible rice grasshopper (Oxya chinensis) in processed food products

Interest in using insects as an alternative source of food for humans is increasing. However, few analytical methods provide accurate information about the presence of insect species in processed foods. In this study, we developed a fast real-time PCR assay based on a TaqMan probe that can be performed within 40 min to detect edible rice grasshopper in commercial food products. A rice grasshopper-specific primer pair and probe targeting the cytochrome c oxidase subunit 1 (COI) gene were newly designed, having an amplicon size of 110 bp. The specificity of this primer pair and probe was verified using 19 insects and five crustaceans and no cross-reactivity was obtained against the non-target species. The absolute limit of detection (LOD) was 0.5 pg of rice grasshopper DNA, and as low as 0.1% of rice grasshopper was detected in raw, heat-treated, and autoclaved binary insect mixtures. To evaluate the effect of food matrix, binary mixtures containing rice grasshopper in wheat were used additionally, and at least 0.1% of target species was detected using this assay. The applicability of this assay was confirmed using nine commercial food samples labeled as containing rice grasshopper or locust. The fast real-time PCR developed in this study is a specific and sensitive method for identifying edible rice grasshopper in various food samples.

Rapid and Sensitive Determination of Vanillin Based on a Glassy Carbon Electrode Modified with Cu2O-Electrochemically Reduced Graphene Oxide Nanocomposite Film

A facile cuprous oxide nanoparticles functionalized electro-reduced graphene oxide modified glassy carbon electrode (denoted as Cu2O NPs-ERGO/GCE) was fabricated via a simple physical adsorption and electrochemical reduction approach. Cyclic voltammetry and second-order derivative linear scan voltammetry were used to investigate the electrocatalysis oxidation of vanillin on the Cu2O NPs-ERGO/GCE. The compound yielded a well-defined voltammetric response in 0.1 M H2SO4 at 0.916 V (vs. saturated calomel electrode (SCE)). A linear calibration graph was obtained in the concentration range of 0.1 μM to 10 μM and 10 μM to 100 μM, while the detection limit (S/N = 3) is 10 nM. In addition, the Cu2O NPs-ERGO/GCE presented well anti-interference ability, stability, and reproducibility. It was used to detect vanillin sensitively and rapidly in different commercial food products, and the results were in agreement with the values obtained by high performance liquid chromatography.

Untargeted DNA-based methods for the authentication of wheat species and related cereals in food products

New food commodities, particularly pasta, bread and cookies, made with mixed flours containing ancient wheat species and other cereals, have become popular in recent years. This calls for analytical methods able to determine authenticity of these products. Most DNA-based methods for the authentication of foodstuff rely on qPCR assays specifically targeting each plant species, not allowing the identification of unsearched ingredients. Moreover, the discrimination among closely related plant species, particularly congeneric ones like Triticum spp, remains a challenging task. DNA fingerprinting through tubulin-based polymorphism (TBP) and a new assay, TBP light, have been optimized for the authentication of different wheat and farro species and other cereals and tested on a set of commercial food products. The assay has a sensitivity of 0.5–1% w/w in binary mixtures of durum wheat in einkorn or emmer flour and was able to authenticate the composition of test food sample and to detect possible adulterations.

Variation in Seed Allergen Content From Three Varieties of Soybean Cultivated in Nine Different Locations in Iowa, Illinois, and Indiana.

Soybean (Glycine max) is an important food stock, and also considered an allergenic food with at least eight well characterized allergens. However, it is a less prevalent allergen source than many other foods and is rarely life-threatening. Soybean is incorporated into commonly consumed foods, and therefore, the allergens pose a potential concern for individuals already sensitized. The protein profile of soybean can be affected by several factors including genetic and environmental. To investigate how soybean allergen content may be affected by genetics and/or environment, nine soy allergens were quantified from three commercial soybean varieties grown at nine locations in three states within a single climate zone in North America; Iowa, Illinois, and Indiana, United States. Quantitation was achieved using liquid chromatography-selected reaction monitoring (LC-SRM) tandem mass spectrometry with AQUA peptide standards specific to the nine target allergens. Quantitation of allergen concentration indicated that both genetics and location affected specific allergen content. Seven of the nine allergens were significantly influenced by genetics, with the exceptions of glycinin G4 and KTI 3. The allergens P34, Gly m Bd 28k, glycinin G3, and KTI 1 showed statistically significant impact from location as well, but at a lower threshold of significance compared with genetics (cultivar/variety). This dataset contributes to our understanding of the natural variation of endogenous allergens, as it represents a sampling of soybeans grown in a controlled, distributed plot design under agronomic conditions common for commercial soybean food and feed production. The aim was to build upon our recent understanding of how allergens are expressed as part of the overall soybean proteome.

Direct pentaplex PCR assay: An adjunct panel for meat species identification in Asian food products

A direct pentaplex PCR assay was developed for the identification of meat from sources other than those declared on the packaging. Species-specific primers were designed, based on the mitochondrial cytochrome oxidase I (COI) gene. The assay amplified specific DNA fragments from dog (230 bp), duck (283 bp), buffalo (363 bp), goat (396 bp), and sheep (477 bp). The proposed method is capable of identifying target species accurately and is reproducible, sensitive and robust for use with real-world foods and food products. In total, 26 of 117 meat and commercial food products tested were shown to contain DNA from species not declared on the label.

Assessment of peanut allergen Ara h1 in processed foods using a SWCNTs-based nanobiosensor.

The goals of this research were to develop a rapid single-walled carbon nanotube (SWCNT)-based biosensor and to employ it to commercial food products for Ara h1 detection. The SWCNT-based biosensor was fabricated with SWCNTs immobilized with antibody (pAb) through hybridization of 1-pyrenebutanoic acid succinimidyl ester (1-PBASE) as a linker. The resistance difference (ΔR) was calculated by measuring linear sweep voltammetry (LSV) using a potentiostat. Resistance values increased as the concentration of Ara h1 increased over the range of 1 to 105ng/L. The specific binding of anti-Ara h1 pAb to antigen including Ara h1 was confirmed by both indirect ELISA kit and biosensor assay. The biosensor was exposed to extracts prepared from commercial processed food containing peanuts, or no peanuts, and could successfully distinguish the peanut containing foods. In addition, the application of present biosensor approach documented the precise detection of Ara h1 concentrations in commercially available peanut containing foods.

Potential Use of Bacillus coagulans in the Food Industry.

Probiotic microorganisms are generally considered to beneficially affect host health when used in adequate amounts. Although generally used in dairy products, they are also widely used in various commercial food products such as fermented meats, cereals, baby foods, fruit juices, and ice creams. Among lactic acid bacteria, Lactobacillus and Bifidobacterium are the most commonly used bacteria in probiotic foods, but they are not resistant to heat treatment. Probiotic food diversity is expected to be greater with the use of probiotics, which are resistant to heat treatment and gastrointestinal system conditions. Bacillus coagulans (B. coagulans) has recently attracted the attention of researchers and food manufacturers, as it exhibits characteristics of both the Bacillus and Lactobacillus genera. B. coagulans is a spore-forming bacterium which is resistant to high temperatures with its probiotic activity. In addition, a large number of studies have been carried out on the low-cost microbial production of industrially valuable products such as lactic acid and various enzymes of B. coagulans which have been used in food production. In this review, the importance of B. coagulans in food industry is discussed. Moreover, some studies on B. coagulans products and the use of B. coagulans as a probiotic in food products are summarized.

Titanium dioxide nanoparticles translocate through differentiated Caco-2 cell monolayers, without disrupting the barrier functionality or inducing genotoxic damage.

The widespread use of titanium dioxide nanoparticles (TiO2 NPs) in commercial food products makes intestinal cells a suitable target. Accordingly, we have used the human colon adenocarcinoma Caco-2 cells to detect their potential harmful effects. Caco-2 cells can differentiate in to enterocytic-like cells, forming consistent cell monolayers and are used as a model of the intestinal barrier. Using both undifferentiated and differentiated Caco-2 cells, we have explored a set of biomarkers, aiming to evaluate undesirable effects associated to TiO2 NP exposure. Results indicate non-toxic effects in exposures ranging 1-200μgml-1 . Significant differences were observed in cell uptake, with a higher amount of incorporated TiO2 NPs in undifferentiated cells, as visualized using confocal microscopy. In well-established monolayers, translocation was detected using both confocal microscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopy. In spite of the observed uptake and translocation, TiO2 NP exposures did not modify the integrity of the monolayer, as measured using the transepithelial electrical resistance and Lucifer yellow methods. The potential genotoxic effects in differentiated cells were evaluated in the comet assay, with and without formamidopyrimidine DNA glycosylase enzyme to detect oxidatively the damaged DNA bases. Although some changes were detected at the lower dose (10μgml-1 ), no effects were observed at higher doses.

Voltammetric determination of vanillin in commercial food products using overoxidized poly(pyrrole) film-modified glassy carbon electrodes

Voltammetric determination of vanillin in commercial food products using overoxidized poly(pyrrole) film-modified glassy carbon electrodes

Low-Cost and Simple Fabrication of Nanoplasmonic Paper for Coupled Chromatography Separation and Surface Enhanced Raman Detection.

Surface-enhanced Raman scattering (SERS) is a powerful analytical tool which enables the detection and identification of analytes adsorbed on nanostructured noble metals. However, SERS analysis of complex mixtures can be challenging due to spectral overlap and interference. In this report, we demonstrate a method to simplify the identification of mixed-analyte samples by coupling SERS detection with chromatographic separation on a nanoplasmonic paper substrate. This "nanopaper" substrate is a silver coated glass microfiber filter paper which possesses large SERS enhancement and can serve as a stationary phase in paper chromatography. Nanopaper is easily synthesized using the silver mirror reaction, making it a highly accessible technology. Nanopaper was successfully used as a combined paper chromatography-SERS (PC-SERS) substrate in the separation and identification of mixed organic dyes. It was further employed to separate and identify lycopene and β-carotene in commercial food products, demonstrating the versatility and utility of nanopaper in the identification of complex mixtures.

Development of molecular markers for detecting almond, peanut, pine nut, and walnut in commercial food using quantitative real-time PCR

Nuts have been used globally as health foods. However, because nuts cause allergies, people need to be careful when eating food. Mostly foods are labeled, but sometimes intentional or unintentional mixing might occur. In the present study, we report DNA based on marker for the detection of four nuts almond, peanut, pine nut, and walnut using quantitative real-time polymerase chain reaction (qRT-PCR). Species-specific primer sets for four species were designed based on the single-nucleotide polymorphisms and insertion/deletion of the chloroplast gene, matK. The sensitivity of primer sets for the four species studied was assessed by analyzing DNA dilutions at concentration of 0.001–10 ng and binary mixtures of 0.1–100% of heat-treated and non-heat-treated samples. The four primer sets developed in the present study indicated appropriate amplification efficiency and correlation coefficients of the standard curves. In addition, to verify the applicability of these molecular markers, we performed a qRT-PCR with 14 commercial products and successfully detected the matK genes in several commercial food products that were declared to contain nuts. Thus, markers developed could be useful tools for confirming the presence of the four nut species in commercial products.

Managing for Multifunctionality in Perennial Grain Crops.

Plant breeders are increasing yields and improving agronomic traits in several perennial grain crops, the first of which is now being incorporated into commercial food products. Integration strategies and management guidelines are needed to optimize production of these new crops, which differ substantially from both annual grain crops and perennial forages. To offset relatively low grain yields, perennial grain cropping systems should be multifunctional. Growing perennial grains for several years to regenerate soil health before rotating to annual crops and growing perennial grains on sloped land and ecologically sensitive areas to reduce soil erosion and nutrient losses are two strategies that can provide ecosystem services and support multifunctionality. Several perennial cereals can be used to produce both grain and forage, and these dual-purpose crops can be intercropped with legumes for additional benefits. Highly diverse perennial grain polycultures can further enhance ecosystem services, but increased management complexity might limit their adoption.

Cyclodextrin-Promoted Fluorescence Detection of Aromatic Toxicants and Toxicant Metabolites in Commercial Milk Products.

The detection of polycyclic aromatic hydrocarbons (PAHs) and their metabolites in food and in agricultural sources is an important research objective due to the PAHs' known persistence, carcinogenicity, and toxicity. PAHs have been found in the milk of lactating cows, and in the leaves and stems of plants grown in PAH-contaminated areas, thereby making their way into both cow milk and plant milk alternatives. Reported herein is the rapid, sensitive, and selective detection of 10 PAHs and PAH metabolites in a variety of cow milks and plant milk alternatives using fluorescence energy transfer from the PAH to a high quantum yield fluorophore, combined with subsequent array-based statistical analyses of the fluorescence emission signals. This system operates with high sensitivity (low micromolar detection limits), selectivity (100% differentiation even between structurally similar analytes), and general applicability (for both unmodified lipophilic PAHs and highly polar oxidized PAH metabolites, as well as for different cow and plant milk samples). These promising results show significant potential to be translated into solid-state devices for the rapid, sensitive, and selective detection of PAHs and their metabolites in complex, commercial food products.

Food claims and nutrition facts of commercial infant foods.

Composition claim, nutrition claim and health claim are often found on the commercial complementary food packaging. The introduction of complementary foods (CFs) to infants is a turning point in the development of their eating behavior, and their commercial use for Taiwanese infants is growing. In Taiwan, lots of the advertisements for CFs employed health or nutrition claims to promote the products, but the actual nutritional content of these CFs is not clear. The aim of this study was to compare the food claims of commercial complementary food products with their actual nutrition facts. A sample of 363 commercial CFs was collected from websites, local supermarkets, and other food stores, and their nutrition-related claims were classified into composition, nutrition, and health categories. Although the World Health Organization recommends that infants should be exclusively breastfed for the first 6 months, 48.2% of the commercial CFs were targeted at infants younger than 6 months. Therefore, marketing regulations should be implemented to curb early weaning as a result of products targeted at infants younger than 6 months. More than 50% of Taiwanese commercial CFs have high sugar content and more than 20% were high in sodium. Products with health claims, such as “provides good nutrition to children” or “improves appetite,” have higher sodium or sugar content than do those without such claims. Moreover, products with calcium or iron content claims did not contain more calcium or iron than products without such claims. Additionally, a significantly greater proportion of the products with “no added sugar” claims were classified as having high sugar content as compared to those without such claims. Parents cannot choose the healthiest food products for their children by simply focusing on food claims. Government should regulate the labeling of nutrition facts and food claims for foods targeted at infants younger than 12 months.

Oat of this world: Defining peptide markers for detection of oats in processed food

AbstractPeople affected by Coeliac disease rely on the purity and accurate labeling of food products in order to follow a strict gluten‐free diet, the only treatment for Coeliac disease. The safety of oats in the gluten‐free diet remains controversial because they contain the gluten‐like avenins. In the present study, global proteomic analyses were performed via LC‐MS/MS on gluten‐enriched fractions extracted from 22 diverse oat cultivars. A panel of oat peptides was assessed using multiple‐reaction monitoring mass spectrometry to define peptide markers that were unique to oats but were present in all 22 oat cultivars. The method was successfully applied to: (1) the detection of oat contamination in spelt, rice, rye, and buckwheat flours; and (2) the analysis of 7 highly processed commercial food products. The oat peptide markers were detected at high levels in a breakfast cereal and a muesli where oats were a named ingredient, but the presence of oats was also noted in 3 of the 5 breakfast cereals where oats were not named as an ingredient. LC‐MS/MS represents a rapid, sensitive, robust and reproducible method for detecting oat contamination in both processed and unprocessed foods.

A closer look at Sporidiobolales: Ubiquitous microbial community members of plant and food biospheres

ABSTRACTCarotenoid-containing yeasts in Sporidiobolales (Microbotryomycetes, Pucciniomycotina, Basidiomycota) have been reported from contrasting ecosystems, including marine, soil, phylloplane, polar ice, and many others. Here, we present several analyses drawing on 583 new isolates collected from various substrates around the globe and publicly available sequences from numerous published environmental studies. We provide a multilocus phylogenetic reconstruction of the order, estimates for total species richness, a snapshot of global distribution patterns, and analysis of niche preferences in Sporidiobolales, emphasizing their occurrence in commercial crops and food products. We evaluated loci commonly used in fungal phylogenetics, finding that RNA polymerase II subunits 1 and 2 (RPB1, RPB2) are of little utility in this group. We have reconfirmed the monophyly of Sporidiobolales with three well-supported genera, which are, in descending order of number of species, Rhodotorula, Sporobolomyces, and Rhodosporidiobolus. From our data, we estimate ca. 260 species in Sporidiobolales, of which 42 are described, and ca. 52,000 species in Pucciniomycotina. The majority of data regarding Sporidiobolales are from North America and Europe, highlighting severe knowledge gaps for most of South and Central America and Africa.

Undeclared Food Allergens and Gluten in Commercial Food Products Analyzed by ELISA.

Undeclared allergen(s) in commercial food products are responsible for many food recalls, as reported by regulatory agencies in various countries, including the United States. Correct allergen labeling practices are essential for the safety of food-allergic consumers. However, this practice may be hindered by the introduction of allergens all along the food supply chain, including unintentionally through cross-contact. To understand the pervasiveness of undeclared allergen(s) in commercial food products, the objective of this review is to summarize the prevalence of undeclared milk, egg, hazelnut, peanut, soy, and gluten as detected by ELISA from previously published surveys. The prevalence of undeclared allergen(s) in products with or without an advisory statement was also summarized and compared. As compiled by this review, there are some food categories that may be at higher risk for containing undeclared allergen(s). However, the data on prevalence and amount of allergen present may vary widely within any particular allergen or food category. Factors, such as food survey product selection, geography, awareness of allergen/gluten issues, and/or the choice of ELISA method, may be responsible for such differences.

Highly Sensitive Matrix-Independent Quantification of Major Food Allergens Peanut and Soy by Competitive Real-Time PCR Targeting Mitochondrial DNA.

The development of two competitive real-time PCR assays for the quantitative detection of trace amounts of two major food allergens, peanut and soybean, is reported. In order to achieve very low detection levels for both allergens, we established PCR primers and probes targeting mitochondrial DNA sequences. We were able to demonstrate that this approach led to an increase in detection sensitivity in the range of at least 1 order of magnitude compared with published assays targeting nuclear DNA. Furthermore, we generated corresponding competitor molecules, which were used as internal standards to compete with matrix effects that are evident during DNA extraction and PCR amplification in heterogeneous analytical matrixes like food. According to the recently described competitive quantitative PCR method published by Holzhauser et al. (2014), we performed threshold calibration against milk powder spiked with 10 ppm peanut and soy. Matrix-independent quantitative determination of peanut and soy could be demonstrated for three different calibrated food matrix standards in a range between 1 and 100 ppm. The data presented indicate that both assay concepts are powerful analytical tools for the quantitative detection of trace amounts of peanut and soy in commercial food products.