Optimization of a viability PCR method for the detection of Listeria monocytogenes in food samples

Postprint (author's final draft

Microbiological quality of commercial dairy products

The purpose of this research was to assess the hygienic properties of commercially available dairy foods. The products surveyed included liquid milks (pasteurized and UHT-treated), cultured dairy products (kefir, cultured buttermilk, sour cream, yogurt, probiotic fermented milks), cheeses (quarg products, soft, semi-hard, hard, and extra hard cheeses made from bovine, caprine, and ovine milk), processed cheeses, butters, butter creams, dried milks, and ice creams. A total of 320 samples were purchased from food stores located in the western part of Hungary. Upon collection, all products were taken to the laboratory and were stored as required until analysis. Although none of the samples tested contained Salmonella spp. or Listeria monocytogens, approximately 14% of them failed to meet the legal requirements in terms of overall hygienic quality. The share of non-compliant samples was especially high among cheeses

Quantification of Listeria monocytogenes in salad vegetables by MPN-PCR

The aim of this study was to assess the most probable number-polymerase chain reaction (MPN-PCR) technique for detection of Listeria monocytogenes in salad vegetables in comparison with reference EN ISO 11290-2 and Food Drug Administration Bacteriological Analytical Manual method using artifcial and naturally contaminated samples. Based on recovery of L. monocytogenes from artifcially contaminated samples, MPN-PCR showed a moderate correlation (R=0.67) between spiking concentration and microbial levels which was better than the FDA-BAM method (R=0.642) and ISO 11290-2:1998 method (R=0.655). With naturally contaminated samples, it was found that L. monocytogenes was detected in 25% of the vegetable samples using MPN-PCR; 15% of the samples by the FDA-BAM method and 8% of samples using ISO 11290-2:1998 method. Overall, MPN-PCR was found to be a rapid and reliable method that could facilitate the enumeration of L. monocytogenes in vegetables

Development of Cottage Cheese Technology Using Whey Broth of Linder Flowers

The article presents research results of determining the rational amount of whey broth of linden flowers that favored the increase of the goat cottage cheese quality after adding to cheese seeds.It was established, that under the influence of the rational amount of 10-20 % of broth, introduced to cheese seeds of development batches (D 1, D 2) of the products at its setting (instead of the same amount of eliminated cheese whey), there took place the increase of the protein content by 0,3, 0,5 % and moisture by 0,6, 1,7 %, comparing with the control.The use of the rational amount of broth in development batches favored the increase of the product output of 100 kg of skimmed milk by 0,6, 0,8 %, respectively, comparing with the control.Whey broth of linden flowers also stimulated the development of the healthy microflora, which amount in development batches of the product (D1- D2) was higher in 2,5 and 2,8 times, comparing with an analogous result in the control.It maximally bring commodity parameters of development batches of cottage cheese to requirements of the product, manufactured of cow milk, and increases the number of consumers of goat milk products

Benders decomposition for congested partial set covering location with uncertain demand

In this paper, we introduce a mixed integer quadratic formulation for the congested variant of the partial set covering location problem, which involves determining a subset of facility locations to open and efficiently allocating customers to these facilities to minimize the combined costs of facility opening and congestion while ensuring target coverage. To enhance the resilience of the solution against demand fluctuations, we address the case under uncertain customer demand using $\Gamma$-robustness. We formulate the deterministic problem and its robust counterpart as mixed-integer quadratic problems. We investigate the effect of the protection level in adapted instances from the literature to provide critical insights into how sensitive the planning is to the protection level. Moreover, since the size of the robust counterpart grows with the number of customers, which could be significant in real-world contexts, we propose the use of Benders decomposition to effectively reduce the number of variables by projecting out of the master problem all the variables dependent on the number of customers. We illustrate how to incorporate our Benders approach within a mixed-integer second-order cone programming (MISOCP) solver, addressing explicitly all the ingredients that are instrumental for its success. We discuss single-tree and multi-tree approaches and introduce a perturbation technique to deal with the degeneracy of the Benders subproblem efficiently. Our tailored Benders approaches outperform the perspective reformulation solved using the state-of-the-art MISOCP solver Gurobi on adapted instances from the literature

PELATIHAN PEMASARAN DIGITAL PRODUK DAUR ULANG SAMPAH PLASTIK BAGI KELOMPOK PKK DI SURABAYA

Mitra kegiatan pengabdian ini adalah ibu-ibu PKK di RT 08 RW 05 kelurahan Airlangga kecamatan Gubeng berjumlah 25 orang. Permasalahan yang dihadapi yaitu mitra belum mengetahui cara memasarkan produknya di market place. Penjualan produknya berupa tas serba guna, tudung saji dan ecobrick masih terbatas. Saat ini mitra penjualan hanya di sekitar tempat tinggalnya, sehingga hasil penjualan pun masih sedikit. Seiring kemajuan zaman dan perkembangan teknologi informasi, para pelaku usaha harus mengikuti kemajuan teknologi agar usahanya berkembang. Maka diberikan solusi berupa pelatihan dan pendampingan pemasaran digital produk daur ulang sampah plastik di salah satu market place yaitu shopee. Metode pengabdian: a. Mitra diberi pelatihan pemasaran digital produk daur ulang sampah plastik secara offline; b.) Melakukan pendampingan secara daring melalui media whatsapp group dan video call. Mitra antusias mengikuti pelatihan pemasaran digital karena menambah pengetahuan dan keterampilannya yaitu bisa membuat toko online di Shopee. Saat kegiatan pendampingan diketahui bahwa mitra masih banyak yang belum membuat toko online karena beberapa alasan. Seperti handphone tidak memadai untuk membuat toko online, belum percaya diri dengan kualitas produk yang dijual dan merasa masih kurang variasi produknya sehingga perlu banyak belajar lagi. Mitra telah mengetahui manfaat menggunakan media sosial untuk menawarkan produknya secara luas yaitu melalui Shopee. Oleh sebab itu penyuluhan literasi digital bagi masyarakat perlu terus dilakukan agar bisa mengikuti perkembangan teknologi yang berdampak positif bagi usahanya.&nbsp

Predicting preference-based utility values using partial proportional odds models.

BACKGROUND: The majority of analyses on utility data have used ordinary least square (OLS) regressions to explore potential relationships. The aim of this paper is to explore the benefits of response mapping onto health dimension profiles to generate preference-based utility scores using partial proportional odds models (PPOM). METHODS: Models are estimated using EQ-5D data collected in the Health Survey for England and the predicted utility scores are compared with those obtained using OLS regressions. Explanatory variables include age, acute illness, educational level, general health, deprivation and survey year. The expected EQ-5D scores for the PPOMs are obtained by weighting the predicted probabilities of scoring one, two or three for the five health dimensions by the corresponding preference-weights. RESULTS: The EQ-5D scores obtained using the probabilities from the PPOMs characterise the actual distribution of EQ-5D preference-based utility scores more accurately than those obtained from the linear model. The mean absolute and mean squared errors in the individual predicted values are also reduced for the PPOM models. CONCLUSIONS: The PPOM models characterise the underlying distributions of the EQ-5D data better than models obtained using OLS regressions. Additional research exploring the effect of modelling conditional responses and two part models could potentially improve the results further