This paper describes an approach for the colour-based classification of
RGB images, taken with a common digital CCD camera on inhomogeneous food matrices. The aim was that of elaborating a feature ...selection/classification method independent of the specific food matrix that is analysed, in the sense that the variables that are the most relevant ones for the classification of the analysed samples are selected in a blind way, with no a priori assumptions on the basis of the nature of the considered food matrix. A one-dimensional signal describing the colour content of each acquired digital image, which we have called
colourgram, is created as the contiguous sequence of the frequency distribution curves of the three red, green and blue colours values, of related parameters (also including hue, saturation and intensity) and of the scores values deriving from the PCA analysis of the unfolded 3D image array, together with the corresponding loadings values and eigenvalues. Once a sufficient number of digital images has been acquired, the corresponding colourgrams are then analysed by means of a feature selection/classification algorithm based on the wavelet transform, wavelet packet transform for efficient pattern recognition (WPTER). This approach was tested on a series of samples of “pesto”, a typical Italian vegetable pasta sauce, which presents high colour variability, mainly due to technological variables (raw materials, processes) and to the degradation of chlorophylls during storage. Good classification results (100% of correctly classified objects with very parsimonious models) have been obtained, also in comparison with the visual evaluation results of a panel test.
In industrialized countries enterotoxigenic Escherichia coli (ETEC) is mainly diagnosed as a cause of travellers' diarrhoea, but it is also known to cause foodborne outbreaks. We report an outbreak ...of acute gastroenteritis caused by ETEC serotypes O92:H− and O153:H2 as well as Salmonella Anatum, which affected around 200 students and teachers after a high-school dinner in Greater Copenhagen, Denmark, November 2006. A retrospective cohort study showed that consumption of pasta salad with pesto was associated with an increased risk of illness (attack rate 59·4%; risk ratio 2·6, 95% confidence interval 1·2–5·7). Imported fresh basil used for preparation of the pesto was the most likely source of contamination. Although ETEC is associated with travellers' diarrhoea in Denmark, this outbreak suggests that a proportion of sporadic ETEC infections might be caused by contaminated imported foodstuffs. To improve food safety further, it is important to target this poorly regulated and researched area.
The antimicrobial activity of enterocin AS-48 against Staphylococcus aureus was tested in vegetable sauces, alone and in combination with phenolic compounds. When added alone at 25 microgram/ml, ...AS-48 inactivated all detectable staphylococci in napoletana and pesto sauces stored at 22 degrees C, but it only caused limited growth inhibition when these sauces were stored at 10 degrees C, as well as in other sauces such as carbonara and green sauce for fish. At 80 microgram/ml, AS-48 eliminated all detectable staphylococci in napoletana, pesto, and green sauce for fish regardless of storage temperature, but it still had much more limited effect in carbonara sauce. Antistaphylococcal activity was potentiated significantly when AS-48 was used in combination with the phenolic compounds carvacrol, geraniol, eugenol, terpineol, caffeic acid, p-coumaric acid, citral, and hydrocinnamic acid. The efficacy of the combined treatments depended both on the phenolic compound and the type of sauce. In carbonara sauce stored at 22 degrees C, the combinations of 80 microgram/ml AS-48 and 20 mM hydrocinnamic acid or 126 mM carvacrol reduced viable counts of staphylococci below detection limits for up to 30 days.
The total, soluble and insoluble oxalate contents of the leaves, stems and buds of Good-King-Henry (
) were extracted and measured using HPLC chromatography. The large, mature leaves contained 42% ...more total oxalate than in the small leaves and the soluble oxalate content of the large leaves was 33% higher than the smaller leaves. Cooking the mixed leaves, stems and buds in boiling water for two minutes significantly (
< 0.05) reduced the total oxalate when compared to the raw plant parts. Pesto sauce made from mixed leaves contained 257 mg total oxalate/100 g fresh weight; this was largely made up of insoluble oxalates (85% of the total oxalate content). Soup made from mixed leaves contained lower levels of total oxalates (44.26 ± 0.49 mg total oxalate/100 g fresh weight) and insoluble oxalate made up 49% of the oxalate contents. The levels of oxalates in the Good-King-Henry leaves were high, suggesting that the leaves should be consumed occasionally as a delicacy because of their unique taste rather than as a significant part of the diet. However, the products made from Good-King-Henry leaves indicated that larger amounts could be consumed as the oxalate levels were reduced by dilution and processing.
The volatile fraction of different kinds of
Pesto
genovese, a typical Italian basil-based pasta sauce, was analysed by Headspace Sorptive Extraction (HSSE)-Gas Chromatography–Mass Spectrometry ...(GC–MS) coupled with chemometric methods. Three kinds of commercial samples were considered: (a) non heat-processed shop manufactured, (b) heat-processed industrial and (c) non heat-processed industrial samples. The category of heat-processed samples was easily discriminated by the amounts of the terpene hydrocarbon α-terpinene. In order to distinguish the three categories, multivariate statistical analysis was then performed. Good prediction results were obtained by the combination of Linear Discriminant Analysis (LDA) and Stepwise LDA (STEPLDA): the percentage of correct predictions was 92 for food industry manufactured non heat-processed samples and 100 both for shop manufactured, non heat-processed samples, and for food industry manufactured, heat-processed samples.
One of the major problems for pesto sauce type products is the tendency of oil to cream, causing their alteration and decreasing consumer’s acceptability. In this study, colloidal and oxidative ...stability of pesto samples with (0.5-1.2%) of beeswax was evaluated during storage at 4, 20 and 40°C. The rheological behavior and color analysis was evaluated at the same temperatures. Sensory evaluation by using a hedonic test was also perfomed. Increasing the samples beeswax content increased the pesto colloidal stability. The samples with 0.8-1.2% have the highest stability and overall performed well on sensory analysis. The peroxide values of samples increased significantly (p
This paper describes the development and application of a new analytical method for the analysis of the volatile fractions of
pesto, a typical Italian basil-based pasta sauce, and its ingredients. ...The extraction of the volatile fraction was realized by headspace sorptive extraction (HSSE) and the extracted volatiles were then thermodesorbed, cryoconcentrated in a cooled injector and analysed by gas chromatography-mass spectrometry.
This study shows that despite the great variability detected in the composition of the volatile fractions of several samples of “Pesto Genovese”, the ingredients traditionally used in
pesto preparation (basil, pine nuts, walnuts, cheese, extra-virgin olive oil and garlic) give a significant and distinctive contribution to the
pesto volatile fraction. Thus, the HSSE analysis of “Pesto Genovese” could be very useful for a careful control of the composition of this valuable niche product.
Use of humectants for the stabilization of pesto sauce Severini, Carla; Corbo, Maria Rosaria; Derossi, Antonio ...
International journal of food science & technology,
June 2008, Letnik:
43, Številka:
6
Journal Article
Recenzirano
The stabilisation of preserves through the lowering of water activity (aw) and the reduction of pH value are studied as alternatives to the traditional pasteurising/sterilising treatments. aw of ...samples of pesto has been reduced using two binary systems of humectants: KCl-fructose and KCl-saccharose. The microbiological stability of samples was assessed through the inoculation of Clostridium perfringens spores. Moreover, pH values, aw and colour parameters were measured. The results have pointed out that aw reduction and controlled temperature of storage inhibited the development of C. perfringens. In particular, run 1 (aw 0.92 and temperature 25 °C) allowed a significant increase of the stability time of the samples. The reduction of aw may be a valid alternative to the traditional treatments of stabilisation in maintaining the organoleptic characteristics of the fresh product.
Provider: - Institution: - Data provided by Europeana Collections- Pesto is an Italian sauce but is easily made using Irish produce. Basil and pine nuts easily grow in Ireland.- All metadata ...published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
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