Consumption of foods containing chicken liver has been associated with Campylobacter enteritis. Campylobacters can contaminate the surface of livers post-mortem but can also arise through systemic infection of colonising bacteria in live birds. The use of bacteriophage to reduce levels of Campylobacter entering the food chain is a promising intervention approach but most phages have been isolated from chicken excreta. This study examined the incidence and contamination levels of Campylobacter and their bacteriophage in UK retail chicken liver. Using enrichment procedures, 87% of 109 chicken livers were surface contaminated with Campylobacter and 83% contaminated within internal tissues. Direct plating on selective agar allowed enumeration of viable bacteria from 43% of liver samples with counts ranging from 1.8–> 3.8 log10 CFU/cm2 for surface samples, and 3.0–> 3.8 log10 CFU/g for internal tissue samples. Three C. jejuni isolates recovered from internal liver tissues were assessed for their ability to colonise the intestines and extra-intestinal organs of broiler chickens following oral infection. All isolates efficiently colonised the chicken intestines but were variable in their abilities to colonise extra-intestinal organs. One isolate, CLB104, could be recovered by enrichment from the livers and kidneys of three of seven chickens. Campylobacter isolates remained viable within fresh livers stored at 4 °C over 72 h and frozen livers stored at − 20 °C over 7 days in atmospheric oxygen, and therefore constitute a risk to human health. Only three Campylobacter-specific bacteriophages were isolated, and these exhibited a limited host range against the Camplylobacter chicken liver isolates. All were identified as group III virulent bacteriophage based on their genome size of 140 kb. The application of broad host range group II virulent phages (8 log10 PFU/g) to liver homogenates containing C. jejuni strains of diverse origin at 4 °C resulted in modest but significant reductions in the viable counts ranging from 0.2 to 0.7 log10 CFU/g.

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The objective of this research was to improve the quality of dried corn noodle through the optimization of processing condition using a cookingforming extruder and the addition of monoglyceride. The process conditions was optimized using Response Surface Methodology (RSM) based on two processing parameters i.e., extruder temperatures (80-90°C) and screw speeds (75-125 rpm). The optimum condition of cooking extrusion was obtained at 90°C and 75 rpm. However, the noodle firmness and stickiness were unsatisfactory. The use of 1% Glyseryl Mono Stearate significantly improved the quality of the noodle with acceptable firmness, elasticity, and elongation. However, the cooking loss and stickiness were still high. ABSTRAKPenelitian bertujuan untuk meningkatkan mutu mi kering jagung melalui optimasi proses menggunakan ekstruder pemasak-pencetak dan penambahan monogliserida. Optimasi proses dilakukan menggunakan Response Surface Methodology (RSM) dengan dua variabel proses yaitu suhu ekstruder (80-90ºC) dan kecepatan ulir ekstruder (75-125 rpm). Kondisi proses optimum diperoleh pada suhu 90ºC dan kecepatan ulir 75 rpm. Mutu kekerasan dan kelengketan mi belum memuaskan. Penggunaan 1% Gliseril Mono Stearat dapat meningkatkan penerimaan mutu kekerasan, elastisitas dan elongasi mi secara signifikan. Kelemahan yang muncul adalah cooking loss dan kelengketan mi masih tinggi.Kata kunci: mi kering jagung, Gliseril Mono Stearat, mutu mi, uji penerimaan, Response Surface Methodology

This study aims to evaluate the influence of solvent acids and glycerol as plasticizer on the antimicrobial and physical properties of chitosan films. Three types of acids were used in the same concentration, e.g. 1% acetic acid, 1% citric acid and 1% lactic acid whereas glycerol was fixed on 10% (w/w). In terms of barrier properties, chitosan film obtained by citric acid as solvent showed the lowest water vapour transmission rate (WVTR) followed by chitosan film prepared with lactic acid and acetic acid. Concerning mechanical properties, chitosan film prepared with acetic acid exhibited the highest tensile strength and the lowest percentage elongation. The expected result was obtained where plasticized chitosan films had higher percentage elongation than the unplasticized one. In this study, disc and well diffusion method were used against bacteria, yeast and fungi to characterize antimicrobial activity of the obtained films. When the disc diffusion method was used, all of chitosan films showed an inhibition activity against E. coli, B. cereus and S. aureus whereas no inhibition against Penicillium sp. and Candida sp except chitosan film prepared with acetic acid that showed inhibition against Candida sp. The same result was observed by using well diffusion method with the exception of chitosan solutions prepared with acetic acid solution where they also showed inhibition activity against Penicillium sp. and Candida sp.