Magnetic Mixed Hemimicelles Solid-Phase Extraction of Three Food Colorants from Real Samples

Introducing a specific clean extraction procedure with a minimal matrices effect for food colorant determination is still a challengeable topic and highly recommended. Mixed hemimicelle solid-phase extraction method, based on cetyltrimethylammonium bromide-coated Fe₃O₄/SiO₂ nanoparticles as a novel, simple, and fast preconcentration method, was applied for preconcentration and fast isolation of three synthetic food colorants in foodstuff matrices prior to HPLC-UV-vis determination. The influence of different parameters on extraction efficiency such as surfactant amount, sample pH, time of extraction, desorption condition, and nanoparticles concentration was optimized. Under the optimized conditions, a preconcentration factor of 100 was achieved by extracting 10 mL sample. The limit of detection for the three synthetic food colorants including Tartrazine, Sunset yellow FCF, and Quinoline yellow is 2.50, 1.25, and 2.12 μg/L, respectively. The proposed method was applicable for extraction and preconcentration of three food colorants in various food samples with the food dye contents in the range of 13–105 μg/L.     

Storage stability of low-fat sodium reduced fresh merguez sausage prepared with olive oil in konjac gel matrix

This paper evaluates the nutritional values and stability during refrigerated storage of fresh beef merguez sausage as affected by a reformulation process which modified the fat content both by reducing fat (replacing beef fat with konjac gel) and incorporating olive oil (replacing beef fat with olive oil stabilized in a konjac matrix) and by reducing sodium content, replacing sodium chloride with a salt mixture (containing potassium chloride, calcium chloride and magnesium chloride). A preservative (sodium metabisulphite) was also used to extend the shelf-life of the product. The fat was reduced by 32 to 80% and sodium by over 36%. The reformulation did not negatively affect the sensory evaluation. Low microbiota growth rate and biogenic amines were attributed mainly to the presence of sodium metabisulphite. This preservative could be used in the reformulation to enhance safety and/or extend the shelf-life of this type of product.     

Evaluation of Lepidium sativum seed and guar gum to improve dough rheology and quality parameters in composite rice–wheat bread

The effects of hydrocolloids in rice–wheat flour were studied. Hydrocolloids at 0%, 0.3%, 0.6% and 1% w/w (flour basis) and guar (G), Lepidium sativum seed (L) and guar-L. sativum seed (GL) gum were tested as additives to the rice/flour in various combinations. The quality parameters for the experiment were assessed with farinography, extensography, amylography and texture profile analysis. The evaluation of dough rheology showed that water absorption, dough development time, dough stability and viscosity all increased with the addition of hydrocolloids alone or in a combination. It was demonstrated that G₁L₁ promoted the highest effect. The mixing tolerance index and gelatinization temperature decreased with an increased hydrocolloid concentration. Extensibility value for the dough that incorporated guar and L. sativum seed gum increased with increasing hydrocolloid concentration from 0.3% to 0.6% and then decreased at 1%. The water activity of all bread didn't have significant differences with increasing hydrocolloids concentration but this parameter 24 decreased during storage. Firmness decreased with increasing hydrocolloid concentration and increased with increasing storage time. The sensory evaluation by a consumer panel gave the higher score for overall acceptability to G_0.3L_0.3 and G_0.3L_0.6 samples. The results also showed that G₁L₁, G₁L_0.6 and G_0.6L₁ samples had high specific volume and porosity.     

Efficient PCR-based gene disruption in Saccharomyces strains using intergenic primers

Gene disruptions are a vital tool for understanding Saccharomyces cerevisiae gene function. An arrayed library of gene disruption strains has been produced by a consortium of yeast laboratories; however their use is limited to a single genetic background. Since the yeast research community works with several different strain backgrounds, disruption libraries in other common laboratory strains are desirable. We have developed simple PCR-based methods that allow transfer of gene disruptions from the S288C-derived strain library into any Saccharomyces strain. One method transfers the unique sequence tags that flank each of the disrupted genes and replaces the kanamycin resistance marker with a recyclable URA3 gene from Kluyveromyces lactis. All gene-specific PCR amplifications for this method are performed using a pre-existing set of primers that are commercially available. We have also extended this PCR technique to develop a second general gene disruption method suitable for any transformable strain of Saccharomyces.     

Improving the functionality of biodegradable food packaging materials via porous nanomaterials

Non-biodegradability and disposal problems are the major challenges associated with synthetic plastic packaging. This review article discusses a new generation of biodegradable active and smart packaging based on porous nanomaterials (PNMs), which maintains the quality and freshness of food products while meeting biodegradability requirements. PNMs have recently gained significant attention in the field of food packaging due to their large surface area, peculiar structures, functional flexibility, and thermal stability. We present for the first time the recently published literature on the incorporation of various PNMs into renewable materials to develop advanced, environmentally friendly, and high-quality packaging technology. Various emerging packaging technologies are discussed in this review, along with their advantages and disadvantages. Moreover, it provides general information about PNMs, their characterization, and fabrication methods. It also briefly describes the effects of different PNMs on the functionality of biopolymeric films. Furthermore, we examined how smart packaging loaded with PNMs can improve food shelf life and reduce food waste. The results indicate that PNMs play a critical role in improving the antimicrobial, thermal, physicochemical, and mechanical properties of natural packaging materials. These tailor-made materials can simultaneously extend the shelf life of food while reducing plastic usage and food waste.