scholarly journals Characterization of pasteurized milk spoilage by electronic nose in relation to its selected quality parameters

2021 ◽  
Vol 10 (2) ◽  
pp. 383-397
Author(s):  
Saleem Ehsan ◽  
Zahir Al-Attabi ◽  
Nasser Al-Habsi ◽  
Michel R. G. Claereboudt ◽  
Mohammad Shafiur Rahman
Keyword(s):  
Shelf Life ◽  
Electronic Nose ◽  
Principal Component ◽  
Titratable Acidity ◽  
Bacterial Count ◽  
Quality Parameters ◽  
Accurate Estimation ◽  
Total Bacterial Count ◽  
Microbial Count ◽  
Linear Discriminant

Pasteurized fresh milk requires an accurate estimation of shelf life under various conditions to minimize the risk of spoilage and product losses. Milk samples were stored for 56 h in an oven at 25°C and for 15 days in a refrigerator at 4°C. Samples were analyzed using an electronic nose (e-nose), total bacterial count, titratable acidity and pH to determine the quality of milk. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were used to analyze e-nose data of milk stored at 25°C, and 4°C. A clear shift in quality was identified by the e-nose, which also appeared in the total bacterial count after 24 h and 12 days for storage at 25 and 4°C, respectively. On the other hand, titratable acidity exceeded the normal limits of 0.14 % - 0.21 % after 24 h for storage at 25°C (0.247 ± 0.006 %) and after 15 days for storage at 4°C (0.25 ± 0.01 %). If pH was a good indicator of quality for samples stored at 25°C, it showed no clear trends for samples stored at 4°C. Based on the microbial count data and e-nose output, the milk had a shelf life of 0.3 day (i.e. 8 h) when stored at 25°C. Shelf life was extended to 9 days when stored at 4°C.

scholarly journals Estimation of the shelf-life of halloumi cheese using survival analysis

2012 ◽  
Vol 30 (No. 6) ◽  
pp. 512-519 ◽  
Author(s):  
R. Kamleh ◽  
I. Toufeili ◽  
R. Ajib ◽  
B. Kanso ◽  
J. Haddad
Keyword(s):  
Survival Analysis ◽  
Shelf Life ◽  
Anaerobic Bacteria ◽  
Titratable Acidity ◽  
Bacterial Count ◽  
Microbial Populations ◽  
Total Bacterial Count ◽  
Failure Index ◽  
Good Manufacturing Practices ◽  
Yeasts And Molds

Halloumi cheese blocks, packaged in vacuum polyamide/polyethylene laminate bags, were stored at 5, 15, and 25&deg;C. The changes in total bacterial count, lactic acid bacteria, total anaerobic bacteria, yeasts and molds, pH, and titratable acidity were monitored during the storage. The appearance of the packaged Halloumi cheese exhibited significant correlations with the counts of the different microbial populations inhabiting the cheese. The shelf-life of the stored Halloumi cheese was determined using survival analysis and considering consumer rejection as a failure index. The nominal shelf-lives of Halloumi cheese were 79.6, 37.8, and 2.6 days when stored at 5, 15, and 25&deg;C, respectively. The Q<sub>10</sub> values (shelf-life at T &deg;C/shelf-life at T + 10&deg;C) at 5&deg;C and 15&deg;C were 2.1 and 14.5, respectively. The increase in the counts of different microbial populations during storage highlights the need for adherence to good manufacturing practices and maintenance of low temperatures during the storage and distribution of the packaged Halloumi cheese.

Shelf-life of ‘Golden Reinders’ Apples after Ultra Low Oxygen Storage: Effect on Aroma Volatile Compounds, Standard Quality Parameters, Sensory Attributes and Acceptability

2009 ◽  
Vol 15 (5) ◽  
pp. 481-493 ◽  
Author(s):  
R. Altisent ◽  
G. Echeverría ◽  
I. Lara ◽  
M.L. López ◽  
J. Graell
Keyword(s):  
Shelf Life ◽  
Volatile Compounds ◽  
Principal Component ◽  
Titratable Acidity ◽  
Quality Parameters ◽  
Sensory Attributes ◽  
Soluble Solids ◽  
Oxygen Storage ◽  
Low Oxygen ◽  
Maturity Stages

The aim of this work was to estimate shelf-life potential and understand quality characteristics of ‘Golden Reinders’ apples during ripening after storage under ultra low oxygen (ULO) atmosphere. Fruits, corresponding to two different maturity stages (147 and 155 dafb), were kept at 1 °C in ULO atmosphere (1 kPa O2: 1 kPa CO2) for seven months and subsequently kept at 1 °C in regular air for up to 28 days. Sub-batches were removed weekly and transferred to 20 °C, so that the shelf-life periods at room temperature were 28, 21, 14, 7, and 0 days. Fruit from both maturity stages showed firmness and soluble solids content (SSC) values above the minimum commercial requirements for this variety throughout the post-storage ripening period. However, only earlier harvested fruit maintained high levels of titratable acidity (TA). Production of aroma volatile compounds was low for shorter ripening periods, though it increased progressively as ripeness advanced. Principal component analysis showed the variables that positively influenced acceptability were: octyl acetate, hexyl octanoate, butyl propanoate, propyl pentanoate, and 6-methyl-5-hepten-2-one as aroma volatile compounds; SSC, TA, firmness, and epidermis colour (Hue) as physicochemical parameters; and sourness and sensory firmness as sensory attributes. From a general overview, the optimum shelf-life period for ‘Golden Reinders’ apples would be between 7 and 14 days for both maturity stages.

scholarly journals Preliminary Insights in Sensory Profile of Sweet Cherries

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 612
Author(s):  
Vânia Silva ◽  
Sandra Pereira ◽  
Alice Vilela ◽  
Eunice Bacelar ◽  
Francisco Guedes ◽  
...  
Keyword(s):  
Sweet Cherry ◽  
Prunus Avium ◽  
Sugar Content ◽  
Principal Component ◽  
Titratable Acidity ◽  
Physicochemical Characteristics ◽  
Quality Parameters ◽  
Sensory Profile ◽  
Soluble Solids ◽  
Sensory Data

Sweet cherry (Prunus avium L.) is a fruit appreciated by consumers for its well-known physical and sensory characteristics and its health benefits. Being an extremely perishable fruit, it is important to know the unique attributes of the cultivars to develop cultivation or postharvest strategies that can enhance their quality. This study aimed to understand the influence of physicochemical characteristics of two sweet cherry cultivars, Burlat and Van, on the food quality perception. Several parameters (weight, dimensions, soluble solids content (SSC), pH, titratable acidity (TA), colour, and texture) were measured and correlated with sensory data. Results showed that cv. Van presented heavier and firmer fruits with high sugar content. In turn, cv. Burlat showed higher pH, lower TA, and presented redder and brightest fruits. The principal component analysis revealed an evident separation between cultivars. Van cherries stood out for their sensory parameters and were classified as more acidic, bitter, and astringent, and presented a firmer texture. Contrarily, Burlat cherries were distinguished as being more flavourful, succulent, sweeter, and more uniform in terms of visual and colour parameters. The results of the sensory analysis suggested that perceived quality does not always depend on and/or recognize the quality parameters inherent to the physicochemical characteristics of each cultivar.

scholarly journals The Comparison of Physicochemical Parameters, Antioxidant Activity and Proteins for the Raw Local Polish Honeys and Imported Honey Blends

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2423
Author(s):  
Michał Miłek ◽  
Aleksandra Bocian ◽  
Ewelina Kleczyńska ◽  
Patrycja Sowa ◽  
Małgorzata Dżugan
Keyword(s):  
Antioxidant Activity ◽  
Protein Content ◽  
Soluble Protein ◽  
Protein Profile ◽  
Principal Component ◽  
Quality Parameters ◽  
Total Phenolic ◽  
Native Page ◽  
Linear Discriminant ◽  
Standard Quality

Many imported honeys distributed on the Polish market compete with local products mainly by lower price, which can correspond to lower quality and widespread adulteration. The aim of the study was to compare honey samples (11 imported honey blends and 5 local honeys) based on their antioxidant activity (measured by DPPH, FRAP, and total phenolic content), protein profile obtained by native PAGE, soluble protein content, diastase, and acid phosphatase activities identified by zymography. These indicators were correlated with standard quality parameters (water, HMF, pH, free acidity, and electrical conductivity). It was found that raw local Polish honeys show higher antioxidant and enzymatic activity, as well as being more abundant in soluble protein. With the use of principal component analysis (PCA) and stepwise linear discriminant analysis (LDA) protein content and diastase number were found to be significant (p < 0.05) among all tested parameters to differentiate imported honey from raw local honeys.

scholarly journals Discrimination between Alternative Herbal Medicines from Different Categories with the Electronic Nose

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2936 ◽  
Author(s):  
Xianghao Zhan ◽  
Xiaoqing Guan ◽  
Rumeng Wu ◽  
Zhan Wang ◽  
You Wang ◽  
...  
Keyword(s):  
Herbal Medicine ◽  
Electronic Nose ◽  
Nearest Neighbor ◽  
Herbal Medicines ◽  
Principal Component ◽  
Support Vector ◽  
Linear Discriminant ◽  
Convenient Means ◽  
Electronic Nose System ◽  
Insight Into

As alternative herbal medicine gains soar in popularity around the world, it is necessary to apply a fast and convenient means for classifying and evaluating herbal medicines. In this work, an electronic nose system with seven classification algorithms is used to discriminate between 12 categories of herbal medicines. The results show that these herbal medicines can be successfully classified, with support vector machine (SVM) and linear discriminant analysis (LDA) outperforming other algorithms in terms of accuracy. When principal component analysis (PCA) is used to lower the number of dimensions, the time cost for classification can be reduced while the data is visualized. Afterwards, conformal predictions based on 1NN (1-Nearest Neighbor) and 3NN (3-Nearest Neighbor) (CP-1NN and CP-3NN) are introduced. CP-1NN and CP-3NN provide additional, yet significant and reliable, information by giving the confidence and credibility associated with each prediction without sacrificing of accuracy. This research provides insight into the construction of a herbal medicine flavor library and gives methods and reference for future works.

Comparative study of microbiological, chemical and sensory properties of kefirs produced in Estonia, Latvia and Lithuania

2016 ◽  
Vol 83 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Dea Anton ◽  
Piret Raudsepp ◽  
Mati Roasto ◽  
Kadrin Meremäe ◽  
Sirje Kuusik ◽  
...  
Keyword(s):  
High Performance ◽  
Ion Trap ◽  
Chemical Properties ◽  
Principal Component ◽  
Bacterial Count ◽  
Starter Cultures ◽  
Oxidation Products ◽  
Total Bacterial Count ◽  
Codex Standard ◽  
Primary Oxidation

In the current study the microbiological, sensory and chemical properties of 24 kefirs (12 producers) from Estonian, Latvian and Lithuanian retail market were determined using gas chromatography (GC), high performance liquid chromatography (HPLC-MS/MS-Q-TOF and LC-ion trap MS/MS), spectrophotometry and other methods. Antihypertensive, angiotensin-converting enzyme (ACE) inhibiting, antioxidant and antibacterial peptides were found in the kefir samples. According to the results of principal component analysis of 200 most abundant compounds obtained with HPLC-MS/MS-Q-TOF analysis, Estonian kefirs differed from the rest. Kefirs of Latvian and Lithuanian origin showed similarities in several characteristics, probably related to the starter cultures and technological processes. The fatty acids composition of all Baltic kefirs was uniform. The antioxidant capacity of the kefirs varied slightly, whereas intermediate positive correlation (r= 0·32,P< 0·05) was found between antioxidativity and total bacterial count. The lipid oxidation level, estimated as the content of linoleic and oleic acid primary oxidation products, oxylipins, was very low in all studied kefirs. Only one third of analysed kefirs met the requirements of the minimum sum of viable microorganisms, indicated in the Codex Standard for Fermented Milks.

scholarly journals Development of a Piezoelectric-Based Odor Reproduction System

Electronics ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 870
Author(s):  
Tengteng Wen ◽  
Dehan Luo ◽  
Yongjie Ji ◽  
Pingzhong Zhong
Keyword(s):  
Principal Component Analysis ◽  
Discriminant Analysis ◽  
Linear Discriminant Analysis ◽  
Electronic Nose ◽  
Principal Component ◽  
Component Analysis ◽  
Piezoelectric Transducers ◽  
Linear Discriminant ◽  
Reproduction System ◽  
Machine Olfaction

Odor reproduction, a branch of machine olfaction, is a technology through which a machine represents various odors by blending several odor sources in different proportions and releases them. In this paper, an odor reproduction system is proposed. The system includes an atomization-based odor dispenser using 16 micro-porous piezoelectric transducers. The authors propose the use of an electronic nose combined with a Principal Component Analysis–Linear Discriminant Analysis (PCA–LDA) model to evaluate the effectiveness of the system. The results indicate that the model can be used to evaluate the system.

Shelf-life and sensory assessments reveal the effects of storage treatments with 1-methylcyclopropene on new and established apples

2014 ◽  
Vol 94 (8) ◽  
pp. 1427-1439 ◽  
Author(s):  
Kareen Stanich ◽  
Margaret A. Cliff ◽  
Cheryl R. Hampson ◽  
Peter M.A. Toivonen
Keyword(s):  
Shelf Life ◽  
Principal Component ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Controlled Atmosphere ◽  
Ethylene Concentration ◽  
Industry Standards ◽  
Principal Component Analyses ◽  
Apple Cultivars ◽  
Cultivar Responses

Stanich, K., Cliff, M. A., Hampson, C. R. and Toivonen, P. M. A. 2014. Shelf-life and sensory assessments reveal the effects of storage treatments with 1-methylcyclopropene on new and established apples. Can. J. Plant Sci. 94: 1427–1439. This research used shelf-life and sensory assessments to explore the influence of 1-methylcyclopropene (1-MCP) on four apples (Aurora, Fuji, Nicola™, Salish™). Maturity (internal ethylene concentration, starch clearing index), quality (soluble solids, titratable acidity, firmness) and sensory determinations were conducted on fruit that had undergone air (AIR) or controlled atmosphere (CA) storage treatments with and without 1-MCP. Trained panelists evaluated apples, along with industry standards (Gala, McIntosh and either Fuji or Ambrosia), for eight attributes (crispness, hardness, juiciness, skin toughness, sweetness, tartness, sweet–tart balance and flavour). Data were analyzed using analysis of variance and principal component analyses (PCA) to compare the treatment and cultivar responses. Cultivars responded very differently to CA and 1-MCP. Fruit from AIR with 1-MCP were very similar to CA fruit without 1-MCP; further improvements were not observed when 1-MCP was applied to CA fruit. PCA bi-plots of the shelf-life and sensory assessments revealed that treated Salish™ fruits were more similar to one another than to cultivars from other treatments. This work successfully documented the unique changes associated with the use of 1-MCP on new and established apple cultivars. It will assist industry in applying appropriate storage practices for new and established apple cultivars.

scholarly journals Quality Parameters of Wheat Bread with the Addition of Untreated Cheese Whey

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7518
Author(s):  
Charikleia Tsanasidou ◽  
Ioanna Kosma ◽  
Anastasia Badeka ◽  
Michael Kontominas
Keyword(s):  
Shelf Life ◽  
Protein Content ◽  
Storage Time ◽  
Cheese Whey ◽  
Environmentally Friendly ◽  
Titratable Acidity ◽  
Quality Parameters ◽  
Wheat Bread ◽  
Mold Growth ◽  
Sensory Analyses

Τhe present study was carried out to evaluate wheat bread of three different flour compositions prepared by replacing water with untreated cheese whey (WCB). Bread prepared with water was taken as the control (CB). All breads were stored at 24 ± 1 °C for up to 6 days. Microbiological, physicochemical, and sensory analyses were determined as a function of storage time. WCB had lower total viable counts (TVC) (3.81 log cfu/g for CB and 2.78 log cfu/g for WCB on day 2 of storage) and showed delayed mold growth by 1 day (day 4 for CB and day 5 for WCB). WCB also had lower pH (5.91 for CB and 5.71 for WCB on day 0), higher titratable acidity values (TTA) (2.5–5.2 mL NaOH/10 g for CB and 4.5–6.8 mL NaOH/ 10 g for WCB), and higher protein content (PC) (PC 7.68% for CB and 8.88% for WCB). WCB was characterized by a more intense flavor, reduced hardness but similar cohesiveness, springiness, and adhesiveness compared to CB. Based primarily on sensory (appearance/mold formation) data, the shelf life of WCB was 4–5 days compared to 3–4 days for CB stored at 24 ± 1 °C. The proposed use of whey in bread preparation contributes decisively to the environmentally friendly management of whey.

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