Search Results

You are looking at 1 - 10 of 45 items for :

  • "starter culture" x
  • Refine by Access: All Content x
Clear All

The objective of this study was to assess the influence of three different starter culture combinations and two scalding temperatures on the organic and fatty acid compositions of pasteurized Mihaliç cheeses. For this purpose, starter culture combinations consisting of Propionibacterium freudenreichii, Streptococcus thermophilus, Lactobacillus helveticus, and Leuconostoc mesenteroides subsp. cremoris were used. Two scalding temperatures, 40 °C or 45 °C, were used for cheeses with the same culture combination. Samples were evaluated in terms of organic and fatty acid compositions during 90 days of ripening. Eye formation, which is a characteristic feature of Mihaliç cheese, was seen in all cheese samples. Propionic and lactic acids were the most abundant organic acids detected in the cheeses. The most abundant saturated fatty acid was palmitic acid, followed by myristic and stearic acids. Oleic acid content was the highest among total unsaturated fatty acids. The control cheese had lower levels of short-chain fatty acids, which contribute directly to the cheese flavour.

Restricted access

Sliced ready-to-eat traditional meat products presented in individual packaging with more convenience to the consumer is the way that food industry tries to adapt to the new consumer tendencies.

The current work assessed the survival of Listeria monocytogenes in a contaminated sliced vacuum packed chouriço with different sugar concentrations, two salt levels, and presence/absence of Lactobacillus sakei as starter culture along the storage period at two temperatures (8 °C and 22 °C). Neither the inoculation with L. sakei, nor the addition of carbohydrates influenced the survival of the pathogen. Higher amount of salt resulted in a significant reduction of L. monocytogenes, and storage at the higher temperature displayed a safer product. After 7 days, L. monocytogenes was not detected in any samples. The study of the association of the factors contributing for L. monocytogenes survival by logistic regression showed that increasing the level of salt addition from 1.5% to 3% reduces the odds of survival of L. monocytogenes to about one fifth (0.174). Worthy of attention is the significant reduction in the odds (OR=0.028) of finding viable L. monocytogenes when the samples are stored at room temperature (22 °C), when compared to low temperature (8 °C).

The general and indiscriminate use of refrigeration for meat products might increase the risk of presence of L. monocytogenes. The competitive advantage that L. monocytogenes has at low temperatures, as the potential inhibition of LAB activity, is probably the reason of the observed behaviour. The amount of salt was an important hurdle to control L. monocytogenes growth, so, manufacturing meat products with lower salt contents to meet the demands of healthy products might represent a risk for safety, since high levels of salt together with low aw are the keys for their conservation.

Restricted access

Initiated by the Association “Wine Route of Etyek Wine District”, the objectives of this study were to isolate and identify autochthonous yeast strains from local wines and to determine their oenologically important properties. The first aim of this work was to characterize the taxonomic and phenotypic diversity of the representative Saccharomyces yeast strains that dominate the spontaneous fermentations in this wine district. The results obtained by molecular ribotyping (ARDRA) revealed a strong dominance of S. cerevisiae, but S. bayanus var. uvarum was also present sporadically. Some of the natural isolates exhibited high volatile acid production or poor fermentation capacity, which imply a quality risk in spontaneous fermentations. Most of the isolates, however, displayed good oenological features during lab scale fermentations. As the second aim of this work, the most promising, selected strains were further tested for oenological properties in microvinification scale and, finally, in large scale fermentations. The analytical and sensory analysis proved that selected strains, including S. bayanus var. uvarum, can be used as local starter cultures, which may contribute to the typicality of the local wines in comparison with commercial starters.

Restricted access

flavour and texture. They are also the predominant microorganisms in artisanal cheeses and are active and determinant at various stages of production and ripening ( Nero et al., 2021 ). Isolated LAB can be utilised as starter cultures in cheese processing

Restricted access
Progress in Agricultural Engineering Sciences
Authors:
Judit Perjéssy
,
Ferenc Hegyi
,
Magdolna Nagy-Gasztonyi
,
Rita Tömösközi-Farkas
, and
Zsolt Zalán

fermentation properties – as selected starter culture, microbiological safety and constant quality would be assured. During the past few decades significant success has been achieved in the development of dairy products containing probiotics, such as fermented

Open access

Thirty-three varieties of dairy products were analysed for fat and cholesterol contents, and a high correlation (r=0.983) was found between these two compositional attributes. Cholesterol concentration was independent of processing factors such as heat-treatment of the raw material, use of starter culture, type of the starter organisms employed and whipping or flavouring of the product. The non-fat varieties of fluid, fermented and dried milks showed significantly increased cholesterol-to-fat ratios compared to the other products tested because they contained considerable amounts of small fat globules and, therefore, had a large surface area with cholesterol bound to the fat globule membranes. The results of this study may be useful when establishing dietary guidelines for the general public according to health concerns, when formulating diets for population groups with special requirements or when assessing fat and cholesterol intakes in epidemiological studies aimed at investigating the relationship between diet and health.

Restricted access
Acta Alimentaria
Authors:
P. Havas
,
Sz. Kun
,
G. Styevkó
,
V. Slačanac
,
J. Hardi
, and
J. Rezessy-Szabó

Consumers are becoming more interested in healthy nutrition. To meet consumer requirements, the possibility of the fruit and vegetable juice fermentation by bifidobacteria was investigated. Sour cherry, orange, carrot, and tomato juice was fermented with five Bifidobacterium strains (from human origin and starter culture). The tested strains have grown well in orange, carrot, and tomato juices. The B. longum Bb-46 strain demonstrated the best growth activities. It was found that ratio of the produced acetic and lactic acids are dependent on the Bifidobacterium strain rather than on the fermentation medium. The most intensive inhibition was observed against the Campylobacter jejuni strain. In course of the fermentation the antioxidant capacities slightly decreased, except when the orange juice was fermented with B. lactis Bb-12 and B. longum A4.8. The obtained results may contribute to the design of a novel functional food product.

Restricted access

Lactic fermentation is the most natural way for foodstuffs to reach microbiological stability and prolonged shelf life. The purpose of this research was to screen a spontaneous lactic fermentation during the process of preserving the green olives of Oblica cultivar (the autochthonous Croatian cultivar) in the agriculture cooperative near Split (Croatia). Using API 50CHL and APILAB PLUS software, the species Lactobacillus curvatus was isolated and identified during the second week of the brining process. In the latter phase of the fermentation process, the presence of microorganisms belonging to this genus was not identified, which proves that spontaneous lactic fermentation in the process of preserving green olives of the Oblica cultivar had been incomplete. This was also proved by the values of fundamental physico-chemical features (low pH, high total acidity concentration, inadequate temperature). Presented results show the necessity of applying starter culture in the process of preserving green olives of the Oblica cultivar.

Restricted access

Wine fermentation is a complex microbiological process in which yeasts predominate. It is long debated whether yeasts occurring on the surface of grapes or the resident yeasts on the winery equipment play the primary role in conducting the fermentation. The origin, development, changes and succession of various yeast species can be followed using specific molecular techniques allowing the differentiation and typing of yeast strains. Techniques such as pulsed field gel electrophoresis of chromosomal DNA, restriction fragment length polymorphism analysis, and polymerase chain reaction (PCR)-based methods have recently been employed in studying the microbiology of wine making. These shed new light on the dynamics of fermentation started spontaneously or directed by the inoculation of starter cultures.

Restricted access