Ripening Temperature Research Articles

Kinetic Study of Structural Hardening Mechanisms of PbCdBiSn and PbCdBiMg Alloys for the New Generation of Battery Grids

The study of the return to equilibrium state of PbCdBiSn and PbCdBiMg alloys has been studied. Indeed, two structural states were considered: raw casting alloy and rehomogenized alloy. The experimental temperatures are 20°C and 80°C. The latter temperature was selected because it corresponds to the temperature of ripening of battery grids and extreme temperature for operating a battery. We studied the kinetics of Pb2%Cd1%Bi0,5%Sn and Pb2%Cd1%Bi2%Mg. The activation energy of the alloy without tin remains less than the one with tin and approximate to that with Magnesium.

Effect of increased initial ripening temperature on the sensory characteristics of Reggianito cheese

The effects of increased initial ripening temperature on the sensory characteristics of Reggianito cheese were evaluated in relation to different temperature–time combinations. Control cheeses stored at 12 °C for 6 months and experimental cheeses stored at 20 °C for 2 or 4 weeks then at 12 °C up to 6 months were analysed at 61, 124, and 180 days of ripening by physicochemical, microbiological and quantitative descriptive analysis. The use of an initial increased ripening temperature results in controlled and limited changes on mesophilic lactobacilli growth and in a mild acceleration of the sensory characteristic development of Reggianito cheese.

Bruise susceptibility of banana peel in relation to genotype and post-climacteric storage conditions

The aim of this study was to understand the genotypic factors and post-climacteric storage conditions that affect bruise susceptibility of banana peel. Putative physicochemical indicators of bruise susceptibility, including peel electrolyte leakage (PEL), total polyphenolic content, hardness, water content, and peel thickness, were investigated. Bruise susceptibility is the lowest impact energy needed to produce visible bruising by an object dropped on post-climacteric banana fruit from a pre-determined height, converted into impact energy (20–200mJ with a 20mJ increment). The bananas were stored either at 18°C throughout ripening or at 13°C between the 2nd and 6th day after ethylene induction. Five cultivars with contrasting susceptibility to impact bruises were used. Neither Grande Naine nor hybrid Flhorban925 bruised at the maximum impact energy (200mJ) during ripening whatever the storage conditions. A gradient in bruise susceptibility was observed among the other cultivars: French Corne>Fougamou>hybrid Flhorban916. Bruise susceptibility increased during ripening and was higher in bananas stored at 18°C. The lower ripening temperature resulted in a two-day delay to fruit maturity as well as in bruise susceptibility. Bruise susceptibility was positively correlated with PEL (R=0.78) and to a lesser extent negatively correlated with hardness (R=−0.45), and was not correlated with polyphenolic content. In conclusion, membrane permeability provides the first clue to understanding bruise susceptibility.

Descriptive sensory profile of cow and buffalo milk Cheddar cheese prepared using indigenous cultures

The objective of the study was to compare the sensory profile of Cheddar cheese prepared from cow and buffalo milk using indigenous and commercial cultures. Commercially available and locally isolated, indigenous starter cultures were used to prepare cow and buffalo milk Cheddar cheese. The cheese was ripened at 4 and 12°C and analyzed for descriptive sensory profile by a panel of 10 assessors after 60 and 120d of ripening. On evaluation, the mean scores for odor, flavor, and texture attributes obtained for buffalo milk cheese were significantly higher than those obtained for cow milk cheese. For most of the traits, cheese samples prepared from indigenous cultures and ripened at higher temperature received higher descriptive scores compared with those of commercial cultures and ripened at lower degrees. Milk sources highly significantly affected the “creamy” and “sour” traits of odor; the “creamy,” “smoky,” and “soapy” flavors; and all the texture attributes except “maturity.” Starter cultures considerably influenced the production of “acidic,” “bitter,” “sweet,” and “sour” characteristics. The use of elevated ripening temperature showed noticeable effect on all the characteristics except the “creamy” odor and flavor. Principal component analysis and hierarchical cluster analysis also showed that milk sources, starter cultures, and ripening temperatures significantly influenced the sensory characteristics.

The influence of elevated initial ripening temperature on the proteolysis in Reggianito cheese

The effects of elevated initial ripening temperature on proteolysis in Reggianito cheese were evaluated considering different temperature–time combinations. Control cheeses stored at 12°C for 6months and experimental cheeses stored at 20°C for 2 or 4weeks then at 12°C up to 6months, were analysed at 61, 124, and 180days of ripening by physicochemical analysis, urea-PAGE analysis of the urea-soluble fraction, RP-HPLC analysis on the water-soluble fraction at pH 4.6, and free amino acid analysis. In general, increasing ripening temperature and time resulted in increases of proteolysis products, notably higher levels being observed in experimental cheeses initially stored at 20°C for 4weeks. Principal component analysis showed that those cheeses at 124days of ripening had similar levels of proteolysis products to the control cheeses at 180days of ripening. In conclusion, promising results related to the proteolysis event in Reggianito cheese were obtained, which may help in the selection of a convenient elevated temperature–time combination for accelerating its ripening.

ORGANIC ACID CONTENTS OF BUFFALO MILK CHEDDAR CHEESE AS INFLUENCED BY ACCELERATED RIPENING AND SODIUM SALT

ABSTRACT The effect of sodium chloride on the production of organic acids during ripening of buffalo milk Cheddar cheese at elevated temperature was evaluated. Buffalo milk Cheddar cheese was produced by adding sodium chloride at the rate of 0, 1 and 2% and stored for ripening at 4C and 12C for 120 days. The cheese was evaluated for organic acids i.e., lactic, acetic, citric, pyruvic, formic, butyric and maleic and mineral contents, including sodium, calcium and potassium at 60 and 120 days of ripening. The results showed that elevated ripening temperature accelerated the production of all organic acids and significantly increased their concentrations. However, during ripening, no effect on minerals profile was observed. High level of salt decreased the production of organic acids during ripening irrespective of ripening temperatures. Hence, it was concluded that elevated ripening temperature and enhanced sodium concentrations showed considerable effect on organic acids production. PRACTICAL APPLICATIONS Worldwide, Cheddar cheese is produced from cow's milk, but buffalo milk ranks at the top in Pakistan's milk production and, being nutritionally rich, is more suitable for cheese. Moreover, cheese ripening is a lengthy process and attempts to shorten the ripening time using a range of systems have had varying degrees of success. Organic acids are the major products of glycolysis during ripening and play an integral role in cheese quality. The addition of salt affects the cheese ripening and hence influences the production of organic acids. The project was designed with greater significance to determine the effect of sodium chloride on production of organic acids during accelerated ripening of buffalo milk Cheddar cheese. Practically, the project concluded that the optimal quantity of salt addition should be 1% in cheese manufacturing and recommended the ripening at 12C for 120 days in buffalo milk Cheddar cheese for better compositional profile.

Effect of processing on amine formation and the lipid profile of cod (Gadus morhua) roe

The processing of fish roe leads to changes in its chemical composition, the extent of which depends on the techniques and additives employed. This study aimed to investigate the effects of ripening temperature and the use of sodium benzoate and citric acid on the quality of ripened cod roe, with respect to the contents of volatile base nitrogen (VBN), trimethylamine (TMA), biogenic amines (BA) and on the lipid composition. In comparison with fresh roes, ripened roes presented higher contents of VBN, TMA, BA and the proportion of free fatty acids regardless of the temperature and additives used during the ripening process. The greatest increases were observed in the samples ripened at 17°C without additives, in which histamine was detected at 8.8mg/100g. A low ripening temperature was the main factor responsible for minimising changes in the cod roe composition. The addition of sodium benzoate as a preservative or citric acid to decrease the pH value had a significant effect in maintaining the quality of the cod roes, mainly at high ripening temperature.

Influence of adjuncts as a debittering aids in encountering the bitterness developed in cheese slurry during accelerated ripening

Summary An attempt was made to accelerate the flavour development in cheese base with the help of exogenous proteolytic and lipolytic enzymes (1:1 proportion, each at the rate of 0.025% by weight of cheese-base) and ripening at elevated temperatures (i.e. 20 ± 1 °C) for up to 12 days. To counter the bitterness developed, adjunct cultures were used: viable or attenuated (freeze-shocked or heat shocked). Study of biochemical characteristics, electrophoretic pattern and sensory evaluation of the product were carried out. An acceptable enzyme-modified, lightly salted cheese base was obtained using 0.025% each of proteolytic and lipolytic enzymes, along with 5% starter culture and adjuncts followed by ripening up to 12 days. Freeze-shocked adjunct Lactobacillus helveticus produced enzyme-modified cheese base with no detectable bitterness. The usage of exogenous enzymes, temperature of ripening, ripening period and interactions amongst these parameters had significant (P < 0.01) influence on all of the biochemical characteristics monitored.

THE INFLUENCE OF RIPENING TEMPERATURE ON THE SENSORY CHARACTERISTICS OF REGGIANITO ARGENTINO CHEESE

ABSTRACT The effect of elevated ripening temperature on sensory characteristics of Reggianito Argentino cheese was evaluated. Cheeses ripened at 12 or 18C and 85% relative humidity were analyzed at 62, 123 and 186 days. The sensory characteristics of cheese samples were analyzed through a quantitative descriptive analysis carried out by a trained sensory panel. Although the attribute scores of cheeses ripened at 18C were different from those ripened at 12C, they did not result in atypical Reggianito sensory characteristics. Principal component analysis showed useful groupings resulting that Reggianito Argentino cheeses ripened at 18C during 62 days had similar sensory characteristics to cheeses ripened at 12C during 186 days. The results obtained not only are useful to characterize the ripening of a traditional Argentinean hard cheese, but also to evaluate the effect of an increase of ripening temperature on sensory characteristics of Reggianito Argentino cheese. PRACTICAL APPLICATIONSElevated ripening temperatures offer the most effective, and certainly the simplest and cheapest, method for the accelerating ripening. However, considering the numerous complex biochemical reactions that occur duringripening, unbalanced flavor or off‐flavors may result. In this paper, the ripening of a traditional Argentinean hard cheese was characterized using sensory analysis. The effect of elevated ripening temperature on sensory characteristics in Reggianito Argentino cheese was also evaluated to study the possibility for accelerating its ripening.

The influence of ripening temperature and sampling site on the proteolysis in Reggianito Argentino cheese

The effects of elevated ripening temperature and sampling site on proteolysis in Reggianito Argentino cheese were evaluated. Cheeses ripened at 12 or 18 °C and 85% relative humidity were analysed at 2, 4 and 6 months in 2 sampling zones (central and external). Samples were analysed to determine the physicochemical and proteolysis parameters through the urea-PAGE of the urea-soluble fraction, RP-HPLC analysis of the water-soluble fraction at pH 4.6, and the free amino acid analysis. Proteolysis was significantly affected by ripening temperature and sampling site. Urea-PAGE analysis showed that elevated temperature increased the degradation of α s1- and β-casein. The degradation of α s1-casein was larger in the central zone than in the external one, while β-casein degradation was similar in both zones. The majority peaks detected by RP-HPLC of the water-soluble fraction at pH 4.6 and free amino acids were significantly affected by ripening temperature and sampling site. Glu, His, Val, Leu, and Lys had the higher concentrations. Principal component analysis showed useful groupings when results from chromatograms were studied. In conclusion, the results obtained not only are useful to characterise the ripening of an Argentinean hard cheese, but also to evaluate the effect of an increase of ripening temperature on Reggianito Argentino cheese proteolysis.

Acceleration of cheese ripening at elevated temperature. An estimation of the optimal ripening time of a traditional Argentinean hard cheese

The effect of elevated ripening temperature on physicochemical, biochemical and sensory characteristics in Reggianito Argentino cheese was evaluated to determine the optimal time for cheese ripening at 18 °C that ensures typical cheese characteristics. Cheeses ripened at 12 or 18 °C and 85% relative humidity were analysed at 2, 4 and 6 months. Seventy-eight variables (as determined by urea-PAGE, RP-HPLC of the water-soluble at pH 4.6 fraction, free amino acids, free fatty acids and sensory analysis) were considered for the principal component analysis. The statistical analysis allowed determination of the optimal time for ripening Reggianito Argentino cheese at 18 °C, which was ranged between 2 and 3 months. In conclusion, the results obtained were not only useful in characterising the ripening of an Argentinean hard cheese, but also in evaluating the effect of an increase of ripening temperature on the main physicochemical, biochemical and sensory changes of Reggianito Argentino cheese.

Development of probiotic Cheddar cheese containing Lactobacillus acidophilus, Lb. casei, Lb. paracasei and Bifidobacterium spp. and the influence of these bacteria on proteolytic patterns and production of organic acid

Three batches of Cheddar cheeses (Batch 1, with only starter lactococci; Batch 2, with lactococci and Lactobacillus acidophilus 4962, Lb. casei 279, Bifidobacterium longum 1941; Batch 3, with lactococci and Lb. acidophilus LAFTI® L10, Lb. paracasei LAFTI® L26, B. lactis LAFTI®B94) were manufactured in triplicate to study the survival and influence of probiotic bacteria on proteolytic patterns and production of organic acid during ripening period of 6 months at 4 °C. All probiotic adjuncts survived manufacturing process and maintained their viability of >7.5 log10 cfu g−1 at the end of ripening. The number of lactococci decreased by one to two log cycles, but their counts were not significantly different (P>0.05) in control and probiotic cheeses. No significant differences were observed in composition (fat, protein, moisture, salt content), but acetic acid concentration was higher in probiotic cheeses. Assessment of proteolysis during ripening showed no significant differences (P>0.05) in the level of water-soluble nitrogen (primary proteolysis), but the levels of secondary proteolysis indicated by the concentration of free amino acids were significantly higher (P<0.05) in probiotic cheeses. SDS-PAGE results on hydrolysis of αs-CN after 6 months were consistently higher in probiotic cheeses (19.28%, 46.99% and 63.42% in Batch 1, Batch 2 and Batch 3, respectively). Proteolytic activity, however, remained relatively low for all cheeses due to the low temperature of ripening (4 °C). Results demonstrated that Cheddar cheeses can be an effective vehicle for delivery of probiotic organisms.

Effects of storage temperature and fruit ripening on firmness of fresh cut tomatoes

Tomato fruit (cultivar Belissimo) were harvested at three different stages of ripening, sliced and stored at at 2, 5, 8, 12 and 16 °C. Firmness was measured as the force necessary to cause a deformation of 3 mm, in the outer and the radial pericarp, daily or every two days, depending on the combination of stage of ripening and temperature. For constructing a model, firmness was considered to be built up by a variable part (e.g. pectin based firmness) that changes according to a first order reaction mechanism and a fixed part (e.g. cellulose or structure based firmness) that is invariable under the circumstances under study. The firmness of the tomato slices decreased exponentially during storage, with a reference rate constant of 0.0975 ± 0.0183 J/mol/K for the outer pericarp and 0.0712 ± 0.0328 J/mol/K for the radial pericarp and energy of activation of 87.5 and 94.8 kJ/mol, respectively for outer and radial pericarp. The parameters of the model were estimated using multiple variate non-linear regression analysis with time, temperature and stage of ripening of the fruit at harvest simultaneously as explanatory variables. To combine the information on firmness behaviour during the preharvest and the postharvest period at different temperatures, it was assumed that the process of firmness loss during ripening was the same whether the fruit ripened on the plant or off-vine. So, the initial firmness at the postharvest period depends on the time the tomatoes were allowed to ripen on the plant (stage of ripening). The statistical analysis of the mean values of firmness provided a percentage variance which accounted for 92% and 72% for outer and radial pericarp, respectively. Using a fundamental approach to build the reported model and using all available data and information made it possible to describe and simulate the firmness behaviour of tomato slices as a function of the stage of ripening and the applied storage temperature.

Ripening temperatures in¯uence biosynthesis of aroma volatile compounds in `Kensington Pride' mango fruit

SummaryUniformly green mature `Kensington Pride' mangoes (Mangifera indica L.) were ripened at ®ve temperatures (158C, 208C, 25, 30 or 358C) with 60% r.h. to investigate the effects of ripening temperature on the ripening process and biosynthesis of aroma volatile compounds. The aroma volatile compounds were extracted by headspace solid phase micro-extraction and analysed using a gas chromatograph (GC) ®tted with a ¯ame ionization detector (FID) and recon®rmed by GC-MS (mass spectrometry). An increase in the temperature signi®cantly increased the rate of respiration and total carotenoids in pulp. Increased ripening temperature up to 308C also increased ethylene production in fruit and total fatty acids in pulp. All the fatty acids in pulp increased as the ripening temperature increased during ripening except palmitic, palmitoleic and linolenic acids. However, pulp of the fruit ripened at 258C exhibited signi®cantly higher concentrations of individual fatty acids, except stearic and linoleic acids. Fruit ripened at 208C exhibited signi®cantly higher total monoterpenes, sesquiterpenes as well as most of their individual compounds as compared with all other ripening temperatures. Increased ripening temperature resulted in signi®cantly higher concentrations of tetradecane, b-ionone, esters and alcohols. On the other hand increased ripening temperature tended to decrease aromatics and aldehydes except carvacrol, p-cymen-8-ol and hexanal. There were signi®cant positive correlations between fatty acids and sesquiterpenes, alcohols and esters especially on day seven of ripening. A signi®cant positive correlation between carotenoids and norisoprenoids was also recorded. A ripening temperature of 208C seems to be the best for ripening and biosynthesis of aroma volatile compounds in the `Kensington Pride' mango.

Optimization of solid-phase microextraction analysis for studying change of headspace flavor compounds of banana during ripening.

The changes of headspace flavor compounds of banana during ripening were studied by a solid-phase microextraction (SPME) method. Three temperatures, 20, 25, and 30 degrees C, were used to investigate the temperature effect on the changes of headspace flavor compounds of banana during ripening over a period of 8 days. Banana juice concentration, salt concentration, time, and temperature were investigated for optimizing the SPME method. The most suitable concentrations of banana juice and salt were 33.3 and 20%, respectively. The optimal temperature and time are about 50 degrees C and 48 min, respectively. Increasing ripening temperature could accelerate ripening rate. Ethanol developed most rapidly at 30 degrees C, whereas amounts of the other investigated flavor compounds stored at 25 degrees C were greater than those of the ones stored at 20 or 30 degrees C.

Banana harvest maturity and fruit position on the quality of ripe fruit

SummaryThere is an increasing market demand for smaller banana fruit. The way that this is being addressed involves harvesting some fruits on a bunch at a less advanced stage of maturity. Experiments were carried out to investigate the effect of age of fruit at harvest, position of the fruit on the bunch and different banana varieties on the speed of ripening and the quality of the ripe fruit at two different ripening temperatures after being exposed to exogenous ethylene. The maturity of bananas at harvest affected both the speed of ripening and the quality of the ripe fruit. Speed of ripening of fruit at 13°C was slower the more immature the fruit at harvest, but there was no effect on the speed of ripening of harvest maturity at a ripening temperature of 16°C. The effects of harvest maturity and position of the fruit on the bunch on peel colour and texture were significant but so small that they would be unlikely to affect the consumers' perception in a commercial situation. The higher soluble solids, flavour, sweetness and acceptability after ripening of the more mature fruit at harvest was sufficiently high that consumers could probably detect them.

Influence of milk treatment and ripening conditions on quality of Raclette cheese

The influence of ripening temperature (11, 14, 17, 20 °C) and ripening time (60, 90 days) on sensory properties and melting quality of Raclette cheeses made from raw milk, pasteurised milk and microfiltered milk has been investigated using the 'special cubic model' experimental design. With increased ripening temperature substantial acceleration of ripening was achieved. The higher ripening temperature led to higher counts of propionibacteria in raw milk cheeses, and, inde- pendent of the milk treatment, to higher concentration of free short chain acids, accelerated proteol- ysis, higher aroma intensity, decrease in water content and higher firmness. Raw milk Raclette should be ripened at ≤ 11 °C for 90 days, whereas pasteurised milk Raclette can be ripened at ≤ 14 °C for 90 days and microfiltered milk Raclette at 17 °C for 60 days in order to achieve comparable sen- sory properties and melting quality. Raclette cheese / milk treatment / pasteurization / microfiltration / accelerated ripening / melting quality

Regulation of ethylene and polyamine synthesis by elevated carbon dioxide in cherimoya fruit stored at ripening and chilling temperatures

In this study we focused on the effect of high CO2 level (20%) on ethylene and polyamine biosynthesis in cherimoya (Annona cherimola Mill.) fruits stored at ripening (20˚C) and chilling (6˚C) temperatures. At ripening temperature, CO2 inhibited ethylene production, but 1-aminocyclopropane-1- carboxylate (ACC) oxidase activity was similar to that in ripe control fruits. CO2 treatment led to a decline in putrescine (Put) and a major accumulation of spermidine (Spd) and spermine (Spm) without any effect on arginine decarboxylase (ADC) activity. These results confirm the preferential transformation of Put to Spd and Spm in CO2 -treated fruits. At chilling temperature, the increase in ACC oxidase activity was inhibited and the Vmax of ADC increased. A combination of chilling temperature storage and high CO2 level led to suppression of basal ethylene production while ACC oxidase activity remained unchanged. In addition, fruits held at these conditions had higher polyamine titres than the untreated control. We propose that, in CO2 -treated fruits, the absence of autocatalytic or basal ethylene production, depending on the temperature, may be due to deviation of the S-adenosylmethionine (SAM) pool towards polyamine synthesis, primarily Spd and Spm.

Elevated Temperature Ripening of Reduced Fat Cheddar Made with or Without Lacticin 3147-Producing Starter Culture

The study evaluated the effects of elevated ripening temperature (7 or 12°C) and starter type on the quality of experimentally produced, reduced fat Cheddar cheeses with a moisture content in the nonfat substances of ∼55% (wt/wt). In one treatment, the population of nonstarter lactic acid bacteria in the cheese was markedly reduced at both ripening temperatures through the use of a single-strain culture that both produced and was immune to the broadspectrum bacteriocin lacticin 3147. Elevation of the ripening temperature resulted in significantly higher primary and secondary proteolysis and higher flavor and aroma scores at ripening times ≤150 d. The culture type affected the levels of secondary proteolysis but generally had no significant effect on flavor or texture scores. Cheeses ripened at 12°C were significantly softer than those ripened at 7°C from 60 d onward. Mean texture scores were not significantly influenced by ripening temperature; however, at >150 d, texture scores tended to decrease in cheeses ripened at 12°C to an extent depending on the type of starter culture used. Differences in the rate of growth and the final population of nonstarter lactic acid bacteria (from 103 to 107) in the cheeses had no significant effect on proteolysis or flavor and aroma or body and texture.

Effect of starters on proteolysis of Graviera Kritis cheese

Four cheesemakings of Graviera Kritis cheese (chee ses A-D) were made from a mix- ture of ewe' s and goal' s milk. Three of these were made with mixed cultures of thermophilic + pro- pionic or mesophilic + thermophilic + propionic starters, while the fourth one was made traditionally without starter cultures. The effect of increasing the temperature of ripening was also determined. The pH 4.4-soluble nitrogen (SN) and trichloroacetic acid (TCA-SN) fractions increased mainly during the warm room ripening. The use of starters caused no significant differences in the ratios of nitro- gen fractions of the four mature cheeses (age> 90 d), whatever the ripening temperature. Nitrogen fractions were significantly correlated with cheese age. At 180 d of ripening, the percentage of pH 4.4-SN in total nitrogen (TN) was 20.7-22.8 % and that of TCA-SN in TN was 19.1-19.3 %. Polyacry- lamide gel electrophoretic (PAGE) results showed that chymosin and plasmin action was intense during the maturation of the cheeses. The proportion of hydrophilic peptides was higher in the water soluble nitrogen (WSN) fraction of the cheeses made with starter cultures at both ripening temper- atures. Free amino acids (FAA) were not significantly different in the four types of cheeses, reach- ing 208-246 mmol·kg-' after 180 d of ripening. The changes in total FAA and in the most abun- dant FAA during the ripening were significantly correlated with chee se age (r > 0.940). The ripening at higher temperature increased the main FAA and the total FAA content in ail types of cheeses, in particular in the chee se made without starter cultures. © InralElsevier, Paris.