Determinazione di Acidi Linoleici Coniugati (CLA) in Matrici Alimentari: una Interessante Applicazione Biotecnologica

An overview of the microbiological characteristics of the wooden shelves used in cheese ripening

Cheese ripening is a complex phenomenon affected by several factors. Among these, the influence of the wooden shelves used for aging traditional cheeses is underrated. The surfaces of the wooden boards are in contact with cheese rind for the entire ripening period and develop a microbial community. The aims of this review article is to provide an overview on the microbiological approaches applied to study the biofilms associated to the wooden tools used for dairy productions and to summarize the studies specifically performed on the wooden shelves used to ripen traditional cheeses. A critical discussion is focused on the hygienic aspects and the safety of these systems applied in cheese pro…

Characterization of bacteriocin-like inhibitory substances (BLIS) from sourdough lactic acid bacteria and evaluation of their in vitro and in situ activity

Development of an ad hoc starter culture for the production of functional raw ewes’ milk cheeses through the addition of grape pomace powder

The present work was carried out to select lactic acid bacteria (LAB) resistant to polyphenols in order to develop an ad hoc starter culture for the production of functional fresh ewes’ milk cheeses through the addition of grape pomace powder (GPP). To this purpose, raw ewes’ milk samples were inoculated with individual polyphenols belonging to five classes: flavanols (cathechin, epicatechin and epigallocathechin), flavonols (quercetin), flavones (rutin), hydroxyl-benzoic acid (vanillic acid and syringic acid) and hydroxyl-cinnamic acid (caffeic acid and cumaric acid). These polyphenols are commonly associated with the wine industry by-products and were added in milk to a final concentratio…

EFFECTS OF CITRUS ESSENTIAL OILS ON THE MICROBIOLOGICAL SAFETY OF PRIMO SALE CHEESE

In the last years, the consumers demanding foods with no chemical preservatives for food conservation, determined an interest by the food industries for the use of natural biopreservatives. Several essential oils from various plants and fruits have been characterized for their antibacterial activities in order to select new biopreservatives. The aim of this work was to evaluate the organoleptic effect of citrus essential oils to be applied in the processing of sheeps’ milk “Primo Sale” cheese and the inhibitory effect on the main bacterial pathogens of dairy interest. In order to better evaluate the antibacterial effect, the first approach was based on pasteurized milk, in view of the futur…

New trends in technology and identity of traditional dairy and fermented meat production processes

Interest in ecofood tourism is strictly related to the consumption of products associated with the geographical area visited. Local products are often requested by consumers living far from the production zones (e.g. in bistro restaurants that reproduce the atmosphere of typicality). This phenomenon, if on the one hand guaranteeing the continued popularity of certain traditional foods, highlights the inherent dangers that certain types of food pose. They could spread the risks to a much wider area that they might typically inhabit. The higher the demand for certain products, the more variations of the production processes of the traditional products there will be. This is particularly evide…

Mantenere la tipicità in un mondo che cambia

Proprietà funzionali in latti fermentati da ceppi di Lactobacillus paracasei e Lactobacillus plantarum: influenza dei parametri microbiologici sulla produzione di acidi linoleici coniugati (cla)

Enzimi, esopolisaccaridi e batteriocine

Determinazione di acidi linoleici coniugati (CLA) mediante Ag+-HPLC in latti fermentati da ceppi di Lactobacillus paracasei e Lactobacillus plantarum

Effect of Opuntia ficus-indica Mill. mucilage edible coating on quality of fresh-cut cactus pears during cold storage

Cactus pear [(Opuntia ficus-indica (L.) Mill.] consumption and marketability are limited by the presence of spines and glochids on the fruit surface. Minimally processed cactus pear fruits are characterized by a short shelf life due to the peel removing that increases tissue senescence and deterioration. The aim of this study was to evaluate the effect of O. ficus-indica (OFI) mucilage edible coating on quality, nutraceutical, and sensorial parameters of minimally processed cactus pear. OFI fruits were collected in mid-October and were quickly moved to the nearby laboratory. One-year-old cladodes were sanitized, sliced into squares, and cooked in a microwave oven and mixed using a homogeniz…

Microorganisms of food ice cubes and their transfer to drinks

The present work was carried out to investigate the microbiological characteristics of the ice cubes produced at different levels: 1) home-made (HM) from domestic freezers; 2) produced by ice machines in bars and pubs (BP); 3) produced by ice industries (IN). BP samples were collected from the box stocks. HM and BP samples were transferred into sterile stomacher bags. IN samples were provided in the manufacturers’ plastic bags. Samples were transported into thermal insulated boxes. Five samples per each production level, forming a total of 15 samples (HM1-HM5, BP1-BP5, IN1-IN5), were collected in duplicate in two consecutive months. Each ice sample was thawed in 1 L sterile Dhuram’s bottle …

Molecular approach for the rapid identification, in situ detection and monitoring of sourdough lactobacilli

Microbiological characterization of the biofilms of wooden shelves used for ripening of traditional raw milk cheeses produced in Sicily (South Italy).

The production of artisanal Sicilian cheeses is generally carried out with wooden equipment. For centuries, wood has been the main material used in cheese making due to its availability, low cost and resistance over time. Among dairy wooden equipment, the wooden vat used for milk curdling plays a role of paramount importance to inoculate the bulk milk with desired lactic acid bacteria (LAB) responsible for the acidification of the curd. In the last few years, the biofilms associated to these containers have been object of study of different research groups, mainly Italian and French, but so far, very little is known about the microbiological characteristics of the wooden shelves used for ch…

Optimization of environmental conditions for kefiran production by kefir grain as scaffold for tissue engineering

The aim of this work was to investigate the fermentation medium and environmental requirements for the production of exopolysaccharide (EPS) Kefiran from natural culture (Kefir grains). We have found that the fermentation medium and temperature are critical for Kefiran production during the 24 h cultivation of kefir grains. The Kefiran obtained from fat cow milk was used to evaluate its potential application as scaffold for tissue engineering. Kefiran scaffold were obtained via solvent casting and direct quenching. Thermal and morphology features were evaluated by DSC and SEM, respectively.

Microbial dynamics during green Sicilian table olive fermentations

The production of green table olives is traditionally a spontaneous fermentation carried out by indigenous microflora. Variability of microbial raw material may result in changes in the qualitative aspects of final products (Silvestri et al., 2009). Table olives of five different green table olive cultivars (four Sicilian Brandofino, Castriciana, Nocellara del Belice and Passalunara and the Spanish Manzanilla) were produced according to a semi-industrial technology, in which lactic acid bacteria (LAB) role is partially replaced by lactic acid addiction. Transformation processes were studied by a combined strategy consisting of chemical, microbiological and sensory analyses. Yeasts harboured…

Ecology and technological capability of lactic acid bacteria associated with Grillo grapevine used as base wine for Marsala production.

Lactic acid bacteria (LAB) have a defining role in winemaking process since their activities determine an important contribute to wine quality. Besides sulphur dioxide, lysozyme is becoming a common supplement in wine for bacterial growth inhibition (Sonni et al, 2009). It is a natural enzyme with muramidase activity working against a wide range of LAB, including Oenococcus spp., Pediococcus spp., Lactococcus spp. and Lactobacillus spp. (Cunningham et al, 1991). To obtain a first mapping of LAB inhabiting Marsala wine production area, grapes of “Grillo” variety were harvested from five vineyards different for climatic and agronomic parameters. A Marsala base wine large-scale process was fol…

Microbial diversity of traditional Sicilian cheeses

Traditional Sicilian cheeses are manufactured in small size farms with raw milk from animals of indigenous breeds and without the addition of starter cultures. In order to transform milk into cheese, the presence of lactic acid bacteria (LAB) is required. The main sources of desirable LAB are generally the milk, the rennet, the equipment used during processing and the dairy environment. In the last years, the microbial characterisation of traditional Sicilian cheeses, such as Caciocavallo Palermitano, Protected Designation of Origin (PDO) Pecorino Siciliano and PDO Vastedda della valle del Belìce have been the object of different studies conducted by our research group. To this purpose, the…

I batteri lattici delle cariossidi del grano: influenza geografica, varietale e del periodo di invecchiamento

Il presente articolo riporta i dati di alcune ricerche volte a risalire all’origine dei batteri lattici degli impasti acidi. A tal proposito, i batteri lattici del frumento di quattro varietà moderne sono stati monitorati a partire dalle spighe. Le cariossidi ospitavano livelli di microrganismi inferiori rispetto a quelli rilevati sulle spighe e queste ultime livelli inferiori rispetto alle semole. La minore biodiversità lattica è stata riscontrata sulle cariossidi, mentre le semole hanno mostrato la maggiore ricchezza di specie e ceppi. Al fine di valutare la resistenza dei batteri lattici del grano durante l’invecchiamento, le cariossidi di due varietà antiche e due moderne di grani duri …

The effects of the traditional producing system on physicochemical, microbial and sensory properties of Caciocavallo Palermitano cheese

Caciocavallo Palermitano (CP) is a traditional cheese made with raw milk from cows of Sicilian local breeds fed pasture-based diets in extensive farms (EXT), processed by an artisanal technology (ART) based on wooden tools and the action of native microflora. CP is obtained also in intensive farms (INT) where milk from cows of specialized breeds fed dry diets is transformed by advanced procedures (ADV) using a stainless steel equipment and lactic acid starter cultures. This research was planned to investigate the changes in cheese properties due to production system and ripening., Milk was collected 3 times from an EXT and an INT farm and processed in ART and ADV conditions. The 12 produced…

Damage to Strawberries Caused by Simulated Transport

The quality and condition of perishable products delivered to the market and their subsequent selling prices are directly affected by the care taken during harvesting and handling. Mechanical injury, in fact, occurs at all stages, from pre-harvest operations through post-harvest handling, packing and transport to the market. The main implications of this damage are the reduction of the product’s quality and economical losses related to the shelf life diminution. For most perishable products, the shelf life is relatively short and it is typically dictated by microbial growth related to the application of dynamic and static loads during transportation. This paper presents the correlation betw…

Purification and characterization of an intracellular family 3 β-glucosidase from Lactobacillus sanfranciscensis CB1

Lactobacillus sanfranciscensis CB1 uses cellobiose and other β-glucosides (methyl-β-glucoside, arbutin, amygdalin and salicin) as carbon sources. A hexameric ca. 288 kDa β-glucosidase was purified to homogeneity from Lact. sanfranciscensis CB1 by four chromatographic steps. The enzyme was optimally active at pH 7.5 and 40°C. It had a pI of ca. 4.38 and a D55°C value of ca. 27 sec. Almost total inhibition was found with sulfhydryl-modifying agents and divalent cations such as Cu2+, Co2+, Hg2+, Ni2+ and Fe2+ at a concentration of 2 mM. The enzyme was active towards β-(1→4) substrates such as p-nitrophenyl-β-D-glucoside, -D-galactoside and -L-rhamnoside, and cellobiose. The sequencing of four …

Effect of environmental and nutritional factors on the production of bacteriocin-like inhibitory substances (BLIS) by Enterococcus faecium strains

Aproximaciones para mejorar el crecimiento de bacterias lácticas iniciadoras OM13 durante las primeras etapas de producción de aceitunas verdes de mesa estilo español

The present research aimed at determining the optimal conditions for the lactic acid fermentation of green Spanish-style table olives. The work is a follow-up, and focuses on the performance of the commercial starter strain Lactobacillus pentosus OM13 by applying an acclimatization step and the addition of nutrients, and concentrations of lactic acid that were previously investigated. The acclimatization of the cells warranted the dominance of the starter culture even at an inoculation level of 2 Log cycles lower than that commonly used in standard fermentation. A significant effect was found in terms of acidification kinetics within the first week of fermentation, with the highest decrease…

Aspetti microbiologici del latte crudo mantenuto a diverse temperature per la produzione di Grana Trentino

Ecologia microbica e caratteristiche fisico-chimiche di lieviti naturali della regione Abruzzo