Search results

The aim of this paper is to study the microbiological profile of the ackee fruit during maturation.

Ackees at ripening stage five, mature but unopened, were allowed to ripen naturally on the trees or on ripening racks used in commercial processing. The microbiological profile of fruits from this stage to that where they had ripened to the point just prior to decay (stage ten) were assessed. Aerobic and anaerobic mesophilic and thermophilic sporeformers and vegetative cells, total coliforms, E. coli, lactic acid bacteria, yeasts and molds at each stage were determined using standard methods.

The number of microorganisms on the tree‐ripened fruits was higher than those ripened on racks. Mesophilic aerobic and anaerobic spore‐forming organisms were present in greater numbers than thermophiles at all stages of maturity. Coliforms, excluding E. coli, were found on the tree‐ripened ackees particularly in the latter stages of ripening. Lactic acid bacteria and yeasts and molds found on both tree and rack‐ripened fruit may be the predominant agents in the microbiological spoilage of ackees during ripening.

This study is the first to assess the microbiological profile of ackees during ripening. It indicated that the relatively low levels of microorganisms of economic or public health significance during both tree‐ and rack‐ripening processes would not affect the commercial sterility of the canned product, even with a moderate thermal process (F_o of 3). It also suggests that controlled rack‐ripening of ackee fruit during commercial processing could improve the microbial quality of the processed product.

This work encompasses the various laboratory-based and portable methods evolved in recent times for sensitive and selective detection of ethylene for fruit-ripening application. The role of ethylene in natural and artificial fruit ripening and the associated health hazards are well known. So there is a growing need for ethylene detection. This paper aims to highlight potential methods developed for ethylene detection by various researchers, including ours. Intense efforts by various researchers have been on since 2014 for societal benefits.

The paper focuses on types of sensors, fabrication methods and signal conditioning circuits for ethylene detection in ppm levels for various applications. The authors have already designed, developed a laboratory-based set-up belonging to the electrochemical and optical methods for detection of ethylene.

The authors have developed a carbon nanotube (CNT)-based chemical sensor whose performance is higher than the reported sensor in terms of material, sensitivity and response, the sensor element being multi-walled carbon nanotube (MWCNT) in comparison to single-walled carbon nanotube (SWCNT). Also the authors have developed infrared (IR)-based physical sensor for the first time based on the strong IR absorption of ethylene at 10.6 µm. These methods have been compared with literature based on comparable parameters. The review highlights the potential possibilities for development of portable device for field applications.

The authors have reported new chemical and physical sensors for ethylene detection and quantification. It is demonstrated that it could be used for fruit-ripening applications A comparison of reported methods and potential opportunities is discussed.

The purpose of this study was to investigate the chemical, textural and sensory properties of some starter cultures fruit-added Golot cheese.

Six types of Golot cheeses were produced in this study. While the control sample contained no starter cultures, five different starter culture combinations (GS1: Streptococcus thermophilus, Lactococcus lactis subsp. cremoris, L. lactis subsp. lactis and Lactobacillus bulgaricus; GS2: S. thermophilus and L. bulgaricus; GS3: S. thermophilus; GS4: S. thermophilus and Lactobacillus helveticus; and GS5: S. thermophilus, L. lactis subsp. cremoris and L. lactis subsp. lactis) were applied to the other cheese samples using an immersion technique. Then, all cheeses were vacuum-packed and ripened at 4 ± 1°C for three months and their chemical, biochemical, sensory and textural analyses were performed on the 2nd, 15th, 30th, 60th and 90th days of ripening.

Results indicated that generally starter cultures have positive effects on the chemical, biochemical and sensory properties of Golot cheese. Considering the final values, the addition of starter cultures enhanced the ripening index of Golot cheeses (8.4%–9.2%), except the GS3 (7.4%), compared to the control (8.1%). At the end of the ripening period, meltability values of GS4 (16.5 mm) cultured cheeses were higher than those of other cultured cheeses (13.0–15.5 mm) and control cheese (14.5 mm). While lipolysis values were low in fresh cheese, it increased during ripening. Overall, GS3 (2.46 acid degree value [ADV]) and GS4 (2.40 ADV) had the highest lipolysis rate, while GS1 (2.14 ADV) had the lowest (p = 0.07). Electrophoretograms indicated that the highest fragmentation of α- and ß-casein occurred in GS5 (48.43%) and GS1 (44.24%), respectively. Also, GS5 was the most appreciated and preferred cheese in terms of sensory. Regarding texture, hardness, cohesiveness, adhesiveness, springiness and gumminess values were determined to be statistically important in terms of ripening time and cheese variety (p < 0.01).

Consequently, all starters had a positive impact on Golot cheese samples and among all S. thermophilus and L. helveticus starter were determined to be the most applicable one considering ripening, texture, sensory and melting properties.

Artificial fruit ripening is hazardous to mankind. In the recent past, artificial fruit ripening is increasing gradually due to its commercial benefits. To discriminate the type of fruit ripening involved at the vendors’ side, there is a great demand for on-sight ethylene detection in a nondestructive manner. Therefore, this study aims to deal with a comparison of various laboratory and portable methods developed so far with high-performance metrics to identify the ethylene detection at fruit ripening site.

This paper focuses on various types of technologies proposed up to date in ethylene detection, fabrication methods and signal conditioning circuits for ethylene detection in parts per million and parts per billion levels. The authors have already developed an infrared (IR) sensor to detect ethylene and also developed a lab-based setup belonging to the electrochemical sensing methods to detect ethylene for the fruit ripening application.

The authors have developed an electrochemical sensor based on multi-walled carbon nanotubes whose performance is relatively higher than the sensors that were previously reported in terms of material, sensitivity and selectivity. For identifying the best sensing technology for optimization of ethylene detection for fruit ripening discrimination process, authors have developed an IR-based ethylene sensor and also semiconducting metal-oxide ethylene sensor which are all compared with literature-based comparable parameters. This review paper mainly focuses on the potential possibilities for developing portable ethylene sensing devices for investigation applications.

The authors have elaborately discussed the new chemical and physical methods of ethylene detection and quantification from their own developed methods and also the key findings of the methods proposed by fellow researchers working on this field. The authors would like to declare that the extensive analysis carried out in this technical survey could be used for developing a cost-effective and high-performance portable ethylene sensing device for fruit ripening and discrimination applications.

The purpose of this study was to determine the sweetness and antioxidant profile‐based nutritional quality of non‐netted orange fleshed muskmelon (cv Maduri) fruit during its development and ripening.

The important nutritional quality determining parameters like sugars, ascorbic acid, carotenoids, phenolics and total antioxidant activity were quantitatively analyzed at five sequential stages of development and ripening of muskmelon. The activities of sugar metabolizing enzymes such as sucrose phosphate synthase and sucrose synthase were evaluated. Further, antioxidant enzymes like peroxidase, polyphenol oxidase and superoxide dismutase which played a significant role in scavenging reactive oxygen species were also assayed.

The results of the present study demonstrated that the sugars got accumulated in high amount in the ripened muskmelon fruit, indicating it as a high sucrose accumulating genotype. However, sucrose phosphate synthase and sucrose synthase exhibited inconsistency in their activities. Phenolics also got accumulated initially with their maximum quantity in the pre‐ripened stage, but thereafter they decreased. Superoxide dismutase and polyphenol oxidase exhibited a progressive synergetic relationship of scavenging of reactive oxygen species with the development and ripening of fruit.

This study revealed that non‐netted muskmelon is a nutritionally rich fruit with significant accumulation of antioxidants and having an added potential source of sweetness.

The purpose of this paper is to estimate physico‐chemical, biochemical and microbiological changes during the three‐month ripening of the Polish traditional raw smoked fermented meat product Kumpia wieprzowa, produced from pork shoulder without fore‐shank.

After one, two and three months, the pH, a_w, chemical composition, the content of nitrogen – total and soluble – as well as the profile of aromatic compounds and microflora, were evaluated.

During ripening, the water content decreased from 62.7 percent to 47.5 percent, while the protein and fat amount increased from 20.8 percent to 25.0 percent and from 9.7 percent to 16.3 percent, respectively; the a_w decreased from 0.95 to 0.88 and pH from 5.80 to 5.35. The proteolytic changes, measured by free amine groups and Nsoluble content, as well as the quantity of free fatty acids and percentage of most of the volatile compounds increased, particularly during the first two months of ripening. The total number of aerobic microorganisms, and Lactobacillaceae decreased during ripening from 7.9 to 6.2 and 5.6 to 4.7 log cfu/g, respectively. The count of coagulase‐negative cocci changed from 5.3 to 5.2 log cfu/g.

Kumpia wieprzowa is a unique pork product, entered on the List of Polish Traditional Products in 2005. Up to the present, the properties of Kumpia wieprzowa were not recognized and published in the scientific literature, in spite of its very interesting raw material (shoulder spontaneously fermented as a whole large primal cut).

Increased reliance on major food crops has caused shrinking of the food basket. Therefore, the aim of the present study is to introduce underutilised fruit of Karanda (Carissa carandus L.) for its commercial exploitation.

The present study elucidates the physiological changes that prevail in the fruits of Karanda during its successive stages of growth and ripening. Changes in sugars, starch, proteins, phenols, amino acids, role of various enzymes and rate of ethylene and respiration has been used as parameters to access the physiological changes taking place.

Notable change was observed in its colour from green to deep blue/black, accumulation of sugars and proteins, degradation of starch, phenols and free amino acids. Cell wall degrading enzymes (polygalactouronase and pectin methylesterase) and antioxidant enzymes (catalase and peroxidase) showed their active role, while that of cell wall degrading enzyme cellulase and hydrolyzing enzymes (amylase and invertase) were not active during the growth and ripening of the fruit. Increased levels of respiration and ethylene production determined it to be a climacteric type of fruit.

The study does not provide information regarding the other nutritional parameters of the fruits like vitamins and minerals.

The physiological changes in relation to growth and ripening would be useful in determining the maturity indices for harvesting and utilization of this underutilised Karanda fruit.

The purpose of this study was to establish the degree of ripening of natural goat cheese used as a raw material; to formulate a spreadable processed cheese with creamy consistency; and to determine the level of each process variable.

Cheeses of various ripening times were selected for the formulation through cluster analysis. The effect of the final moisture was studied using the same proportion of fresh and ripened cheeses in the formulation, and three melting temperatures were tested.

Goat cheeses ripened for 10, 20 and 40 days were chosen for the formulation of spreadable processed cheese. Final moisture content of 63.0 ± 0.1 per cent was selected (p = 0.0008). Melting temperature at 85.0 ± 0.1°C for 9.0 ± 0.5 min was suitable to homogenize the cheese mass (p = 0.001). The level of variables was validated by changing the proportions of natural goat cheeses selected. Four formulations were obtained with a consistency similar to that of the commercial reference.

Processed cheese is produced by blending shredded natural cheeses of different types and degrees of ripening. The use of ripening goat cheeses as a raw material in processed cheeses contributes to the added value of the local goat milk chain. Goat cheeses have an acid and slightly salty taste and medium to long persistence.

The results of this work can be used by processed cheese manufacturers to better understand the impact of goat cheese ripening on processed cheese quality. The industry can also use these results to introduce the product onto the market and plan their marketing campaign.

The terms ripeness and maturity, when applied to fruit and vegetables, are often difficult to define. They relate to the time at which the commodity is in the appropriate state for harvesting and for eating. Although the extremes of under‐ripeness and over‐ripeness are fairly easily defined, exactly when the ripe state is achieved between these two extremes is to some extent subjective and, in the case of a fruit like the tomato, may depend on the degree of sweetness or acidity an individual may find attractive. In fruit during ripening there is a well coordinated series of changes in the composition of the fruit which lead from the unripe to the ripe condition and which give obvious changes in colour, texture, taste and aroma which are readily perceived by the senses. With vegetables, however, there are no obvious changes of this type and maturity is exceedingly difficult to define. However, there are changes in the chemical and physical structure of vegetables during the maturation period and, although these are of a subtle nature, they can affect the quality of the vegetables as food.

The purpose of this paper was to develop a chemo-resistive sensor based on TiO₂–WO₃ composite material to detect and estimate ethylene released from the fruit ripening process to ensure food safety.

The ethylene sensor has been fabricated using TiO₂–WO₃ composite material through the sol-gel method.

The sensitivity of the sensor obtained using the pre-calibrated ethylene is found to be 46.2 per cent at 200 ppm ethylene concentration, and the proposed sensor could measure 8 ppm as the lowest concentration.

The sensor was tested for continuous ethylene detection during natural ripening of fruits and hence is useful for ensuring food safety through discrimination of the type of fruit ripening. A TiO₂–WO₃ composite ethylene sensor is developed for the first time.