Zein and tannic acid hybrid particles improving physical stability, controlled release properties, and antimicrobial activity of cinnamon essential oil loaded Pickering emulsions.

Pickering emulsion loading essential oil has demonstrated a promising strategy as delivery system in food preservation, but localization in stability and antimicrobial activity limits application. In this study, Pickering emulsions co-loaded with tannic acid and cinnamon essential oil (ZTC) have been developed based on zein and tannic acid complexes (ZT) mediated interfacial engineering. Fourier transform infrared, fluorescence spectroscopy, and molecular docking results indicated tannic acid altered the structural of zein. Interfacial tension results indicated that tannic acid accelerated the adsorbed speed of zein particles by decreased interfacial tension (11.99-9.96 mN/m). ZT5 formed a viscoelastic and dense layer in oil-water interface than that for other ZTs, which improved stability and control release performance of ZTC. Furthermore, the ZTC showed an effective antimicrobial activity against spoilage organisms Pseudomonad paralactis MN10 and Lactobacillus sakei VMR17. These findings provide new insight for developing co-loaded multiple antimicrobial agents within Pickering emulsion as a delivery system.

Development of Plastic/Gelatin Bilayer Active Packaging Film with Antibacterial and Water-Absorbing Functions for Lamb Preservation.

In order to extend the shelf life of refrigerating raw lamb by inhibiting the growth of microorganisms, preventing the oxidation of fat and protein, and absorbing the juice outflow of lamb during storage, an active packaging system based on plastic/gelatin bilayer film with essential oil was developed in this study. Three kinds of petroleum-derived plastic films, oriented polypropylene (OPP), polyethylene terephthalate, and polyethylene, were coated with gelatin to make bilayer films for lamb preservation. The results showed significant improvement in the mechanical properties, oxygen, moisture, and light barriers of the bilayer films compared to the gelatin film. The OPP/gelatin bilayer film was selected for further experiments because of its highest acceptance by panelists. If the amount of juice outflow was less than 350% of the mass of the gelatin layer, it was difficult for the gelatin film to separate from lamb. With the increase in essential oil concentration, the water absorption capacity decreased. The OPP/gelatin bilayer films with 20% mustard or 10% oregano essential oils inhibited the growth of bacteria in lamb and displayed better mechanical properties. Essential oil decreased the brightness and light transmittance of the bilayer films and made the film yellow. In conclusion, our results suggested that the active packaging system based on OPP/gelatin bilayer film was more suitable for raw lamb preservation than single-layer gelatin film or petroleum-derived plastic film, but need further study, including minimizing the amount of essential oil, enhancing the mechanical strength of the gelatin film after water absorption.

Combined Effect of Cinnamon Bark Oil and Packaging Methods on Quality of Fresh Lamb Meat Patties during Storage at 4 °C.

The present study aimed to investigate the effects of adding cinnamon bark oil (CBO) on the quality of ground lamb meat, considering different packaging conditions, including modified atmospheric packaging (MAP) using Hengxian HX-300H and overwrapped packaging. The CBO was incorporated into lamb meat samples at three different levels: 0% (control), 0.025% and 0.05% (v/w). The samples were then subjected to three packaging methods: MAP1 (80% O2 + 20% CO2), MAP2 (40% O2 + 30% CO2 + 30% N2) and overwrapped packaging and stored at 4 °C for 0, 4, 8, 12 and 16 days. The findings of the present study revealed that the addition of 0.025% and 0.05% CBO under MAP1 condition significantly improved the color of the meat samples after 12 days of storage at 4 °C (p < 0.05). The overwrapped samples exhibited higher levels of thiobarbituric acid reactive substances (TBARS) compared to all other treatments, starting from day 4 of storage (p < 0.05). Furthermore, microbial counts were notably higher in the overwrapped samples than in all other samples after day 8 of storage (p < 0.05). In conclusion, the combination of 0.05% CBO with MAP proved to be an effective strategy for enhancing the color stability and oxidative stability of ground lamb meat. These results suggest that CBO can be utilized as a beneficial protective agent in meat packaging processes.

Influence of adding cinnamon bark oil on meat quality of ground lamb during storage at 4 °C.

The study explored the preservative effects of adding different levels of cinnamon bark oil on meat quality of ground lamb. The longissimus thoracis et lumborum (LTL) meat samples were treated with 0 (control), 0.01%, 0.025%, 0.05%, and 0.5% of cinnamon bark oil and stored at 4 °C for 16 days. Microbial populations of TVC, lactic acid bacteria, and Enterobacteriaceae were reduced up to 0.6 to 1.9 log CFU/g than control from day 4 to 16 during storage. The samples adding 0.025% and 0.05% cinnamon bark oil showed lower thiobarbituric acid reactive substance (TBARS) and pH values but higher L⁎, a⁎, R630/580 and Chroma values than all the other samples (P < 0.05). The relative content of oxymyoglobin was higher for 0.01%, 0.025%, and 0.05% cinnamon bark oil samples after 12 days of storage than other treatments (P < 0.05). In conclusion, cinnamon bark oil of 0.025% and 0.05% had a better preservative effect on the lamb meat quality during storage.

Effects of phosphorylation on the activity of glycogen phosphorylase in mutton during incubation at 4 °C in vitro.

The aim of this study was to assess the effects of the phosphorylation levels of glycogen phosphorylase on its activity in mutton sarcoplasmic protein samples during incubation at 4 °C. Samples of sarcoplasmic proteins from mutton longissimus thoracis muscles were prepared and separated into three treatment groups to obtain glycogen phosphorylase with different phosphorylation levels, which were (1) treated with protein kinase A, (2) treated with alkaline phosphatase, and (3) left untreated (control). Glycogen phosphorylase phosphorylation levels and activity as well as the levels of related endogenous substances were assessed. The results showed that phosphorylation of glycogen phosphorylase in mutton promoted its activity during incubation at 4 °C. The activity of glycogen phosphorylase was also influenced by other factors (glycogen, glucose, glucose 6-phosphate, ATP, etc.) in vitro. The combined effects of phosphorylation and endogenous substances on glycogen phosphorylase activity varied at different incubation times.

Lactobacillus reuteri I5007 Modulates Intestinal Host Defense Peptide Expression in the Model of IPEC-J2 Cells and Neonatal Piglets.

Modulation of the synthesis of endogenous host defense peptides (HDPs) by probiotics represents a novel antimicrobial approach for disease control and prevention, particularly against antibiotic-resistant infections in human and animals. However, the extent of HDP modulation by probiotics is species dependent and strain specific. In the present study, The porcine small intestinal epithelial cell line (IPEC-J2) cells and neonatal piglets were used as in-vitro and in-vivo models to test whether Lactobacillus reuteri I5007 could modulate intestinal HDP expression. Gene expressions of HDPs, toll-like receptors, and fatty acid receptors were determined, as well as colonic short chain fatty acid concentrations and microbiota. Exposure to 108 colony forming units (CFU)/mL of L. reuteri I5007 for 6 h significantly increased the expression of porcine ß-Defensin2 (PBD2), pBD3, pBD114, pBD129, and protegrins (PG) 1-5 in IPEC-J2 cells. Similarly, L. reuteri I5007 administration significantly increased the expression of jejunal pBD2 as well as colonic pBD2, pBD3, pBD114, and pBD129 in neonatal piglets (p < 0.05). This was probably associated with the increase in colonic butyric acid concentration and up-regulating expression of Peroxisome Proliferator-Activated Receptor-γ (PPAR-γ) and G Protein-Coupled Receptor 41 (GPR41) (p < 0.05), but not with stimulation of Pattern-Recognition Receptors. Additionally, supplementation with L. reuteri I5007 in the piglets did not affect the colonic microbiota structure. Our findings suggested that L. reuteri I5007 could modulate intestinal HDP expression and improve the gut health of neonatal piglets, probably through the increase in colonic butyric acid concentration and the up-regulation of the downstream molecules of butyric acid, PPAR-γ and GPR41, but not through modifying gut microbiota structure.

Dietary Sodium Butyrate Decreases Postweaning Diarrhea by Modulating Intestinal Permeability and Changing the Bacterial Communities in Weaned Piglets.

BACKGROUND: The vast majority of substances used as alternatives to antibiotics produce inconsistent results and rarely equal the effectiveness of in-feed antibiotics. OBJECTIVE: This study evaluated the effects of the combined use of sodium butyrate (SB) and reduced antibiotics in a piglet diet in promoting performance and to control weaning diarrhea. METHODS: Piglets weaned at 28 d were randomly assigned to a corn-soybean meal control ration [negative control (NC)]; a similar ration with 50 mg kitasamycin/kg, 20 mg colistin sulfate/kg, and 1000 mg encapsulated SB/kg [reduced antibiotics + SB (ASB)]; or to a ration with 100 mg kitasamycin/kg and 40 mg colistin sulfate/kg [positive control (PC)] for 28 d. Performance, diarrhea incidence, intestinal permeability, and changes in the bacterial communities in the ileum and colon were determined. RESULTS: Weight gain and the ratio of weight gain to feed intake were significantly greater in the ASB and PC piglets than in the NC piglets (P < 0.05). Diarrhea incidence was lower in the ASB and PC piglets than in the NC piglets (P < 0.05). Urinary lactulose to mannitol ratios were 25% and 30% lower, respectively, whereas jejunal and colonic occludin protein expressions were significantly greater in the ASB and PC piglets compared with the NC piglets (P < 0.05). In the intestinal mucosa, malondialdehyde was lower in the ASB and PC piglets (by 42% and 43%, respectively), whereas tumor necrosis factor α (TNF-α) was 63% lower in the ASB piglets and 59% lower in the PC piglets compared with the NC piglets (P < 0.05). 16S ribosomal RNA gene sequence analysis revealed a higher colonic Shannon index and a lower colonic Simpson index in the ASB and PC piglets than in the NC piglets. In addition, the ASB and PC treatments caused a striking decrease in Lactobacillaceae and a noticeable increase in Clostridiaceae in the ileal and colonic lumen, as well as increases in Ruminococcaceae, Lachnospiraceae, and Bacteroidetes in the colonic lumen. CONCLUSION: Collectively, our results support an important role for SB in improving performance and decreasing diarrhea incidence in weaned piglets by modulation of intestinal permeability and the bacterial communities in the ileum and colon.

Lactobacillus reuteri I5007 modulates tight junction protein expression in IPEC-J2 cells with LPS stimulation and in newborn piglets under normal conditions.

BACKGROUND: Tight junctions (TJs) maintain the intestinal mucosal barrier, dysfunction of which plays a vital role in the pathophysiology of a variety of gastrointestinal disorders. Previously, we have shown that L. reuteri I5007 maintained the gut epithelial barrier in newborn piglets. Here we aimed to decipher the influence of L. reuteri I5007 on tight junction (TJ) protein expression both in vivo and in vitro. RESULTS: We found that L. reuteri I5007 significantly increased the protein abundance of intestinal epithelial claudin-1, occludin and zonula occluden-1 (ZO-1) in newborn piglets (orally administrated with 6 × 10(9) CFU of L. reuteri I5007 daily for 14 days). In vitro, treatment with L. reuteri I5007 alone maintained the transepithelial electrical resistance (TEER) of IPEC-J2 cells with time. In addition, IPEC-J2 cells were stimulated with 1 µg/mL lipopolysaccharide (LPS) for 1, 4, 8, 12 or 24 h, following pre-treatment with L. reuteri I5007 or its culture supernatant for 2 h. The results showed that LPS time-dependently induced (significantly after 4 or 8 h) the expression of TNF-α and IL-6, and decreased TJ proteins, which was reversed by pre-treatment of L. reuteri I5007 or its culture supernatant. CONCLUSIONS: L. reuteri I5007 had beneficial effects on the expression of TJ proteins in newborn piglets and the in-vitro results showed this strain had a positive effect on TEER of cells and inhibited the reduction of TJ proteins expression induced by LPS. These findings indicated L. reuteri I5007 may have potential roles in protection TJ proteins in TJ-deficient conditions.

Intestinal microbiota succession and immunomodulatory consequences after introduction of Lactobacillus reuteri I5007 in neonatal piglets.

Seventy-two, suckling piglets, obtained from 9 litters standardized to 8 piglets, were assigned to 1 of 3 treatments (n = 24) to compare short-term, early administration with intermittent, longer-term administration of Lactobacillus reuteri I5007. The treatments were a control (given a placebo of 0.1% peptone water from day 1 to 5) or treatments in which 1.7 × 1010 CFU L. reuteri was administrated either daily for 4 days starting on day 1 or every 4th day from day 1 to 17. Five piglets per treatment were killed at 3 time points (day 7, 14 and 21). Denaturing Gradient Electrophoresis of ileal digesta revealed an increase in the presence of L. reuteri I5007 and Clostridium lentocellum (on day 14 and 21) in the every 4th-day treatment and Actinobacillus porcinus (on day 7 and 14) in both L. reuteri treatments, while reducing the abundance of E. coli on day 21 in the every 4th-day treatment. Real-time qPCR of ileal digesta showed an increase in Bifidobacterium spp. on day 14 for both L. reuteri I5007 treatments. An increase in the concentration of lactic acid and a lower pH was observed in the first 4-day treatment on day 7 and the every 4th day treatment on day 14. The relative abundance of mRNA for TGF-ß was increased while that for IFN-γ was decreased in the mesenteric lymph nodes of piglets treated with L. reuteri every 4th day. In conclusion, early intervention with L. reuteri increases the presence of beneficial bacteria and decreases the presence of undesirable microbes in the lower gastrointestinal tract. The changes appear to be mediated by altering the intestinal pH through lactic acid production resulting in favorable bacterial species colonization. A prolonged duration of treatment (i.e. every 4th day) would appear to be superior to treatment only during the first 4 days.

The bacteriocin sublancin attenuates intestinal injury in young mice infected with Staphylococcus aureus.

Sublancin, a bacteriocin, has bactericidal activity against a broad spectrum of gram-positive bacteria. However, studies have not been conducted to determine its in vivo efficacy against potential pathogens. The objective of this study was to investigate the effects of sublancin in a Staphylococcus aureus (S. aureus) infected mouse model which induced intestinal injury. A total of 160, 4-week-old mice were randomly assigned to one of eight treatments. Mice in the control group were injected intraperitoneally with 0.5 mL of 0.9% saline. Mice in the other seven groups were given an intraperitoneal injection of 0.5 mL saline containing 1.0 × 10(10) colony-forming units (CFU)/mL S. aureus. Six hours after inoculation, mice in the control group were again injected with 0.5 mL of 0.9% saline. Mice in the other seven groups were injected intraperitoneally with 0.5 mL of 0.9% saline containing 0, 0.5, 1.0, 2.0, or 4.0 mg/kg body weight (BW) sublancin or 1.0 or 2.0 mg/kg BW ampicillin. The results showed that 4.0 mg/kg sublancin and 2.0 mg/kg ampicillin significantly reduced mice mortality from 55 to 10%. The height and the number of proliferated cells from the intestinal villi in the sublancin and ampicillin treated mice were higher than in the control. We conclude that sublancin has potent antibacterial activity against S. aureus. Therefore, sublancin could find use as an alternative antimicrobial agent for the treatment of gram-positive bacterial infections.