Effect of nanovesicle-encapsulated nisin on growth of Listeria monocytogenes in milk

Commercial nisin was encapsulated in nanovesicles (mean diameter 140 nm) prepared from partially purified soy lecithin. Nisin-loaded liposomes and unencapsulated (free) nisin were initially tested in BHI medium and skim milk inoculated with Listeria monocytogenes and incubated for 48 h at 30 °C. At such abuse temperature conditions, free nisin showed better inhibitory than the liposomal counterparts. Subsequently, the effect of encapsulated or free nisin was evaluated in combination with refrigeration (7 ± 1 °C) in both whole (3.25% fat) and skim (0% fat) milk for up to 14 day. A decrease of 3–4 log cycles in L. monocytogenes counts was observed for free and encapsulated nisin at 0.5 mg/ml concentration. Liposome encapsulation of antimicrobial peptides may be important to overcome stability issues and interaction with food components. The utilization of nanovesicle-encapsulated nisin in combination with low temperatures appeared to be effective to control L. monocytogenes in milk, emphasizing the importance of hurdle technology to assure food safety.     

Clarification of fruit juices by fungal pectinases

This study analyses the efficiency of fungal pectinolytic preparations produced in laboratory and commercial products used in the clarification process of apple, butia palm fruit, blueberry, and grape juices. Two crude enzymatic extracts, produced by Aspergillus niger T0005007-2 (TE1) and Aspergillus oryzae IPT 301 (TE2), were tested in solid-state and submerse cultures, respectively, in comparison to the commercial preparations Pectinex^®Clear and Pectinex^®BE Colour, used for the clarification of clear (apple, butia palm fruit) and dark (blueberry and grape) juices, respectively. With pectinases total activity at 1 U/mL of fruit juice, reactions were conducted at 30 and 50 °C, for 30 and 60 min. Time increase resulted in an improved clarification, whereas temperature increase could not be clearly linked to a greater clarification. When compared to the commercial products, the use of the crude preparation TE1 resulted in similar clarification of apple and blueberry juices. For butia palm and grape juice, however, TE1 presented the highest clarification results, revealing the potential of A. niger T0005007-2 enzymes for commercial application.     

Development of a Topical Insulin Polymeric Nanoformulation for Skin Burn Regeneration: An Experimental Approach

Insulin is a peptide hormone with many physiological functions, besides its use in diabetes treatment. An important role of insulin is related to the wound healing process—however, insulin itself is too sensitive to the external environment requiring the protective of a nanocarrier. Polymer-based nanoparticles can protect, deliver, and retain the protein in the target area. This study aims to produce and characterize a topical treatment for wound healing consisting of insulin-loaded poly-DL-lactide/glycolide (PLGA) nanoparticles. Insulin-loaded nanoparticles present a mean size of approximately 500 nm and neutral surface charge. Spherical shaped nanoparticles are observed by scanning electron microscopy and confirmed by atomic force microscopy. SDS-PAGE and circular dichroism analysis demonstrated that insulin preserved its integrity and secondary structure after the encapsulation process. In vitro release studies suggested a controlled release profile. Safety of the formulation was confirmed using cell lines, and cell viability was concentration and time-dependent. Preliminary safety in vivo assays also revealed promising results.     

Food insecurity and nutrition index: Disaggregation and evidence for Brazilian states

Food security and nutrition is a multidimensional theme consisting of three pillars: food access, availability, and sufficiency. Given food security and nutrition's extent, its measures are usually limited. To address these limitations, this paper proposes the creation of a disaggregated food insecurity index for Brazilian states, with the three dimensions in mind. The results show that while food availability elevates the average of the index, the sufficiency still is a problem. Even though the distribution of and access to food in Brazil has increased in the last years, it was not combined with policies that guarantee its safety and quality, reinforcing the need for specific interventions considering regional particularities.     

A variable neighborhood search heuristic algorithm for the double vehicle routing problem with multiple stacks

This paper addresses the double vehicle routing problem with multiple stacks (DVRPMS) in which a fleet of vehicles must collect items in a pickup region and then travel to a delivery region where all items are delivered. The load compartment of all vehicles is divided into rows (horizontal stacks) of fixed profundity (horizontal heights), and on each row, the unloading process must respect the last‐in‐first‐out policy. The objective of the DVRPMS is to find optimal routes visiting all pickup and delivery points while ensuring the feasibility of the vehicle loading plans. We propose a new integer linear programming formulation, which was useful to find inconsistencies in the results of exact algorithms proposed in the literature, and a variable neighborhood search based algorithm that was able to find solutions with same or higher quality in shorter computational time for most instances when compared to the methods already present in the literature.