Proteolytic fungi isolated from decayed and damaged raw tomatoes and implications associated with changes in pericarp pH favorable for survival and growth of foodborne pathogens

Raw and minimally processed high-acid fruits and vegetables are considered to be at low or no risk for supporting growth of foodborne pathogens. The potential increase in the pH of tissues as a result of fungal growth, however, may enhance the potential for survival and growth. We examined 77 decayed and 138 damaged, raw, ripe tomatoes for the presence of yeasts and molds that produce proteolytic enzymes and other metabolites that can potentially increase the pH of pulp tissue. The pH of decayed and sound radial pericarp tissues (pulp) of decayed tomatoes ranged from 4.7 to 7.8 (mean = 6.2) and 4.3 to 5.8 (mean = 5.0), respectively, whereas the pH of damaged and sound pericarp of damaged tomatoes ranged from 4.2 to 7.8 (mean = 5.2) and 4.2 to 8.0 (mean = 4.9), respectively. The pH of sound pericarp of 8.5% of decayed tomatoes and 3.4% of damaged tomatoes, respectively, was > 5.41. In contrast, the pH of 70% of the decayed tissue and 18% of the damaged tissue was > 5.41. Fungal isolates (n = 371) recovered from decayed and damaged tomatoes on dichloran rose bengal chloramphenicol agar were examined for proteolytic activity on gelatin agar and standard methods caseinate agar. One hundred eight (29%) of the isolates exhibited proteolytic activity on one or both differential media; 96 (89%) were molds, and 12 (11%) were yeasts. The pH of both media increased at the edge of proteolytic fungal colonies. Growth of proteolytic isolates from decayed tomatoes on tomato juice agar (pH = 4.3) and on the surface of tomato juice (pH = 4.1) caused an increase in mean pH values at the colony/medium interface to 7.2 and 6.4, respectively. Results show that some fungi capable of infecting raw tomatoes, as well as the mycoflora incident on tomato surfaces, can increase the pH of pericarp and juice to levels favorable for growth of most foodborne pathogenic bacteria.     

Proteolytic yeasts isolated from raw,ripe tomatoes and metabiotic association of Geotrichum candidum with Salmonella

Metabiotic associations between food-borne fungi and bacteria capable of causing human diseases are a public health concern. A survey of decayed and damaged, uncooked, ripe tomatoes was done to determine the presence and prevalence of yeasts capable of increasing the pH pulp tissue, thus creating a more favorable environment for survival and growth of enteric pathogens. Sixty-two of the 371 (16.7%) fungi isolated from 215 decayed or damaged tomatoes; 12 of the 62 (19.4%) yeasts showed proteolytic activity on gelatin agar (GA) and/or standard methods caseinate (SMC) agar. The pH of tomato pericarp (pulp) tissue from which 9 of the 12 yeasts were isolated ranged from 4.3 to 7.5 (mean=5.3) compared to 4.2-5.1 (mean=4.8) for sound pulp tissue in the same tomatoes. The 12 proteolytic yeasts consisted of four strains of Cryptococcus albidus, two strains each of Debaryomyces hansenii and Trichosporon pullulans, and one strain each of Cryptococcus humicolus, Cryptococcus laurentii, Geotrichum candidum, and Sporidiobolus pararoseus. Survival and growth characteristics of a five-serotype mixture of Salmonella co-inoculated with G. candidum into sound (not chill injured) and chill-injured tomatoes were studied. Storage of sound tomatoes at 15 degrees C for 10 days resulted in an increase in population of 7.6 log(10) cfu of Salmonella/g of a 2-g sample of co-infected pulp tissue. Increases were less in tissue inoculated with Salmonella only, Salmonella on day 0 followed by G. candidum on day 3, or G. candidum on day 0 followed by Salmonella on day 3. Trends were similar in sound inoculated tomatoes stored at 25 degrees C. Growth of Salmonella was enhanced in chill-injured tomatoes compared to sound tomatoes; a population of 10 log(10) cfu/g of chill-injured pulp tissue was reached within 10 days at 25 degrees C. Results clearly show that growth of a proteolytic, alkalinizing yeast such as G. candidum in raw tomatoes enhances conditions for growth of Salmonella. The removal of tomatoes infected with proteolytic yeasts and other fungi from lots intended for minimally processed tomato products is an essential step in reducing the risk of human diseases caused by pathogenic bacteria favored by increased pH of decayed pulp tissue.     

Growth and Corresponding Elevation of Tomato Juice pH by Bacillus coagulans

B. coagulans was inoculated into sterile, tubed tomato juice and growth and pH were observed for 21 days. Juice samples initially at pH 4.5 supported good growth; pH was elevated to 5.0 after 6 days incubation at 35°C. Other tomato juice samples (initial pH 5.0 or 5.5) also supported good growth of these flat-sour bacteria and with corresponding increases in pH. The results indicate that flat-sour spoilage of tomatoes and similar foods may cause decreased acidity, thus possibly allowing outgrowth of Clostridium spores in these water bath-processed foods.     

EFFECT OF BREAK TEMPERATURE AND HOLDING TIME ON PECTIN AND PECTIC ENZYMES IN TOMATO PULP

SUMMARY –The effect of break temperature and holding time on chemical and physical properties of canned tomato pulp and on the activity of polygalacturonase (PG) and pectin esterase (PE) was investigated. Samples preheated above 200°F were slightly higher in pH value and lower in titratable acidity than those preheated at 160°F and 140°F. The gross viscosity and serum viscosity of the canned tomato pulp increased as break temperature increased. A slight increase in serum viscosity was also observed when holding time was lengthened. The effect of break temperature on serum viscosity was much greater than that of holding time. The total pectin content of the tomato pulp as well as that of the serum increased as the break temperature increased. The same observation holds true for the effect of holding time on the total pectin content of the tomato pulp and tomato serum. This was explained by the inactivation of pectic enzymes at higher break temperature and longer holding periods. The level of PE and PG activity in the frozen tomato pulp decreased as break temperature and holding time increased. No PE activity was detected in samples preheated at 180°F for 15 sec. Samples preheated at 220°F for 15 sec showed no PG activity, while those preheated at 200°F for 15–87 sec still show some PG activity with a retention of about 3.54–5.68%. PG in tomatoes may be inactivated by giving the macerated fruits a hot break temperature higher than 200°F. The critical conditions for inactivation of PE (180°F for 15 sec) and of PG (220°F for 15 sec) found in the course of this investigation are supported by the data obtained on pectin analysis and serum viscosity.     

Chemical Characterization of Tomato Juice Fermented with Bifidobacteria

Abstract: The objective of this research was to characterize the chemical properties of tomato juice fermented with bifidobacterial species. Tomato juice was prepared from fresh tomatoes and heated at 100 °C prior to fermentation. Bifidobacterium breve, Bifidobacterium longum, and Bifidobacterium infantis were inoculated in tomato juice and kept at 35 to 37 °C for up to 6 h. Fructooligosaccharide (FOS) was added to tomato juice prior to fermentation. The analyses for brix, total titratable acidity (TTA), pH, color, and lycopene content were conducted to characterize tomato juices fermented with bifidobacterial species. Heat treatment of tomato juice did not cause any significant changes in brix, pH, and TTA. Only the redness of tomato juice was significantly increased, as the heating time increased to 30 min. The tomato juices fermented with B. breve and B. longum exhibited significant decreases in pH (3.51 and 3.80, respectively) and significant increases in TTA (13.50 and 12.50, respectively) (P < 0.05). B. infantis did not cause any significant change in the chemical properties of tomato juice. The addition of FOS further improved the fermentation of tomato juice by bifidobacterial species. The lycopene contents of tomato juice were significantly increased from 88 to 113 μg/g by heat treatment at 100 °C (P < 0.05), however did not exhibit any significant change after fermentation with bifidobacterial species.     

VISCOSITY AND QUALITY OF TOMATO JUICE AS AFFECTED BY PROCESSING METHODS

ABSTRACT

Quality and viscosity of tomato juice is strongly governed by mechanical and thermal abuse during processing. The effect of processing and storage duration on the viscosity and quality parameters of tomato juice was evaluated in the present work. Tomato juice was obtained by two different methods, normal method (NM) and variable method (VM), and was heated by both conventional and microwave hot break treatments. Tomato juice was evaluated for various quality characteristics including precipitate weight ratio, degree of serum separation (DOSS), Brookfield viscosity, lycopene levels, vitamin C, phenols and antioxidant activity. Changes observed in several quality parameters during storage were statistically insignificant. The methods and processing had the greatest contribution toward viscosity, whereas storage duration had no significant effects. Viscosity parameters viz precipitate weight, DOSS and Bostwick consistency revealed that juice processed by VM was more viscous than that of NM, irrespective of the hot break processing used. Ascorbic acid and lycopene content varied significantly with mechanical methods and processing conditions. However, phenolic content and antioxidant activity remained stable. The variable process represents an improvement over the conventional by enabling tomato processors to improve the consistency of the tomato product.

PRACTICAL APPLICATIONS

Quartering or slicing tomatoes followed by hot break processing techniques can significantly improve the quality of tomato juice in terms of reduced degree of serum separation and precipitate weight ratio. The modified technology could be considered as a viable and economical method for small‐ and medium‐scale tomato processors with limited resources and facilities at their disposal.

     

IN-LINE MONITORING OF TOMATO CONCENTRATE PHYSICAL PROPERTIES DURING EVAPORATION

This work continues the development of an ultrasonic sensor system for in‐line measurement of the physical properties of fluid foods. The test system was a semi‐batch evaporator in which juice from three varieties of processing tomatoes was concentrated from 5 to 24 Brix. The physical properties of the tomato concentrates were measured and correlated to ultrasound properties. Speed of sound was linearly correlated with density, soluble solids content and total solids content of the tomato concentrates. Shear viscosity of the tomato concentrates flowing in viscometric pipe flow was evaluated using ultrasonic Doppler velocimetry (UDV). The UDV technique combines a fluid velocity profile and a simultaneous pressure drop to create a rheogram. Simple shear viscosity was modeled as power law behavior for tomato concentrates as a function of solids content for the three processing varieties. Off‐line measurements of apparent viscosity were well correlated to the in‐line measurements.     

Preference Mapping of Fresh Tomatoes Across 3 Stages of Consumption

Tomatoes (Solanum lycoperiscum) are a popular produce choice and provide many bioactive compounds. Consumer choice of tomatoes is influenced by flavor and visual appearance and external texture cues including hand firmness and sliceability. The objective of this study was to determine drivers of liking for fresh tomatoes across 3 stages of consumption. Seven tomato cultivars were ripened to a 6 on the USDA color chart. Trained panelists documented appearance, flavor, and texture attributes of tomatoes in triplicate. Tomato consumers (n = 177) were provided with knives and cutting boards and evaluated tomatoes across 3 stages: appearance (stage 1), slicing (stage 2), and consumption (stage 3). Consumers evaluated overall liking at each stage. Analysis of variance and external preference mapping were conducted. Overall liking was highest during the appearance portion of the test and lowest during the consumption portion (P < 0.05). Drivers of liking at stage 1 were color intensity, even outside color, and overall aroma. Drivers of liking at stage 2 were wetness/juiciness and overall aroma. Wetness/juiciness, seed presence, ripe flavor, and sweet and umami tastes were drivers of liking for tomatoes at consumption (stage 3). Four separate clusters of tomato consumers were identified. Cluster 1 preferred tomatoes with even color, higher color intensity, and flavor intensity. Cluster 2 preferred firm tomatoes. Cluster 3 preferred tomatoes that were soft and at peak ripeness; this cluster also had the highest liking scores for all tomatoes. Cluster 4 consumers generally consumed tomatoes in sandwiches rather than as‐is and preferred tomatoes with even and intense color. Tomato growers can utilize these results to target cultivars that are well liked by consumers.     

Postharvest Ripening Characterization of Greenhouse Tomatoes

The determination of °Brix, pH, titratable acidity and antioxidant composition such as β-carotene, lycopene, and vitamin C was done in greenhouse “Savoura” tomatoes during maturation. The chromatic values L*, a*, b* were determined at the top surface of the tomato, and its strength-deformation curve was tested with a texturometer. Results pointed out that °Brix and titratable acidity did not change during postharvest, while β-carotene, lycopene, and vitamin C contents increased continuously toward the red stage of tomato. The colour values L*, a*, b*, and ratio a*/b* had a good correlation with the maturity stages. Also, a high correlation between lycopene content and (a*/b*) ratio was found, which was well represented with a second order polynomial function (r² = 0.95). This equation permits to appropriately estimate lycopene content of tomato as a function of its color, without any chemical analysis. During ripening, tomato texture changed from firm turgid to soft and the puncture deformation degree increased. Tomato firmness and chromatic values had a good correlation, and the lycopene content was a logarithm function of firmness (r² = 0.81). The strength in puncture test increased linearly with deformation until the bioyield point. The measured force was analyzed as the sum of the compression and the shear forces. The two force coefficients can be considered as tomato properties, independent of the puncture probe. These coefficients were found to decrease during tomato maturation.     

Chemical,antioxidant and sensory properties of tomato‐watermelon‐pineapple blends,and changes in their total antioxidant capacity during storage

A conductometric analysis of the effect of condensate of peroxides generated during lipid oxidation in an accelerated stability test was adapted to test the hypothesis that total antioxidant capacity of tomato products would sometimes increase during processing and in storage. Tomato pulp blends made from a mixture of tomato (Lycopersicon esculentum var Roma VF), watermelon (Citrullus vulgaris var Babylack) and pineapple (Ananas comosus var Smooth cayennes) were analysed for basic quality profiles of dry matter, Brix, titratable acidity (TTA) and pH, total reducing sugars, Component antioxidants phytochemicals and total antioxidant capacity. The lowest sensory score (overall impression) of 4.80 ± 2.59 was recorded for tomato juice while, blend TWP 111p had highest score of 6.20 ± 1.99. There was significant difference (P < 0.05) in the basic quality profile of the pulp blends except for TTA values (0.37 ± 0.02 to 0.45 ± 0.05) and 2‐Furfurals (2.47 ± 0.03 to 2.71 ± 0.01). The fresh blend of 50% tomato, 25% watermelon and 25% pineapple had the highest total antioxidant capacity of 3.69 ± 0.52 mg 100 mL^?1 catechin equivalent. The total antioxidant capacity of the stored pulp increased from 2.95 ± 0.13 to 6.22 ± 0.32 mg 100 mL^?1 catechin equivalent in pasteurised TWP 211p blend by 60 days when stored at 40 °C. Total antioxidant status of tomato‐based fruit mix increased during the first 80 days.     

PARTICLE-SIZE ANALYSIS OF TOMATO POWDER

Particle‐size information is a measure of the quality of processed food products. In this investigation, a study has been made for the particle‐size analysis (PSA) of blanched and unblanched samples of tomato powder. The outcome indicates that the standard percentile reading D (v, 0.5), D (v, 0.1) and D (v, 0.9) for blanched and unblanched tomato‐powder samples are 260.30, 308.78 and 100.49 μm and 108.57, 609.24 and 521.76 μm, respectively. Volume mean diameter [D 4,3] is higher for unblanched sample (335.87 μm) compared with blanched tomato powder (288.41 μm). Surface area mean diameter [D 3,2] is also higher for unblanched sample (200.51 μm) than blanched tomato powder (158.71 μm). Furthermore, the specific surface area (Aw) is higher for blanched sample (0.0378 m²/g) as compared with unblanched sample (0.0299 m²/g). The blanching treatment slightly affects the grinding/milling quality/size‐reduction characteristics and results in uniform particle size, which is depicted by a narrow range of particle‐size distribution of tomato‐powder samples. Blanched tomato powder is finer as compared with unblanched tomato powder. The narrow range of particle sizes of the blanched sample of tomato powder shows stability during particle‐size settlement, as it is a very important and much desirable parameter for its use in processing of another product preparation.     

DEFECTS AND PEELABILITY OF PROCESSING TOMATOES

Peeling is one of the first operations in the manufacture of whole peeled and diced tomatoes, and the peelability of processing tomatoes is significantly affected by the presence of various tomato defects, in particular yellow eye and blossom‐end rot. Tomato maturity also impacts both the percentage of peeled fruit and yield. Immature fruits are typically undercolored and small in size. Sunburned regions on the tomato surface are difficult to peel as well. In this study, we determined the impact of 24 selected tomato defects on tomato peelability and yield of whole peeled tomatoes. There are potential advantages to sorting to remove selected tomato defects early in the process.     

Tomatine,chlorophyll, β‐carotene and lycopene content in tomatoes during growth and maturation

Tomato (Lycopersicon esculentum) plants synthesise nutrients, pigments and secondary metabolites. These include the green pigment chlorophyll, the yellow pigment β‐carotene, the red pigment lycopene and the colourless glycoalkaloid α‐tomatine. The levels of these compounds are strongly influenced by the maturity of the tomatoes. Widely consumed Japanese tomato varieties Momotaro, Momotaro‐T93 and First Memory at five different stages of ripeness, each harvested at 10, 20, 30, 40 and 50 days after flowering of the plants, were analysed for the contents of these compounds. Additionally, tomato clusters from different locations along the vine on the same plant were also evaluated. The results show that chlorophyll and tomatine concentrations decrease rapidly during the growth of the tomatoes. By contrast, β‐carotene and lycopene levels are low in immature and high in mature tomatoes. The location of the tomato clusters and tomato variety did not significantly affect these results. The possible usefulness of these results to optimise health‐promoting effects of tomatoes is discussed. © 2003 Society of Chemical Industry     

Metabiotic Association of Fusarium, Alternaria, and Rhizoctonia with Clostridium botulinum in Fresh Tomatoes

Clostridium sporogenes and C. botulinum grew, and toxin was produced by C. botulinum in a metabiotic relationship with fungi in fresh tomatoes. Fungi of the genera Alternaria, Rhizoctonia and Fusarium were studied. Infection of tomatoes with the fungi increased the pH of tomato tissues as high as pH 8.0. A gradient in pH across the tomato tissue was observed with pH in healthy tissue at approximately normal values (pH 4.3 to pH 4.5). Macerates from tomatoes inoculated with C. botulinum and Alternaria or Fusarium were toxic to mice but Rhizoctonia infected tomatoes did not tend to support toxin production by C. botulinum even though the pH of infected tomatoes was pH 5.3 to 7.6.     

Measuring Mold Infestation in Raw Tomato Juice

A modified fluorescent lectin test for molded raw tomato juice was compared with both the visual mold inspection method conducted by the California Processing Tomato Advisory Board and the Howard mold count (HMC) conducted by 4 commercial tomato processors. The assay quantifies fungal contamination by detecting fungal chitin using FITC-labeled lectin that selectively binds to chitin. The mold content of 100 naturally infected raw tomato juice samples was determined using these 3 methods. The coefficient of determination between the lectin assay and the HMC (r²= 0.73) was better than the coefficient of determination between the California processing tomato visual mold inspection method and the HMC (r²= 0.38). The coefficient of determination between the fluorescent lectin assay and the HMC (r²= 0.73) was comparable to the coefficient of determination between different quality control laboratories' HMC values, which ranged from r²= 0.69 to r²= 0.81. The fluorescent lectin assay had consistently better precision (average CV = 8%) than the HMC (average CV = 38%).     

EVALUATION OF PROCESSING TOMATOES FROM TWO CONSECUTIVE GROWING SEASONS: QUALITY ATTRIBUTES, PEELABILITY AND YIELD

Peelability is an important quality parameter in the selection of tomato cultivars (cvs.) for whole peeled and dice processing. Six processing tomato cvs. were evaluated in two consecutive years to examine the effects of cv., maturity and physical attributes on peelability and yield. Physical attributes of the raw tomatoes (size, weight, pericarp wall thickness, color) and processed paste quality (pH, titratable acidity, soluble solids, Bostwick consistency, serum viscosity, color) were determined. Large variations in physical attributes and paste quality were observed in selected tomato cvs. and maturities. In general, most of the attributes indicative of paste quality were more desirable at the less mature (e.g., pink) stage and declined with maturity. Statistical analysis suggests that there were significant differences in percentage of peeled tomatoes, peel index, and yields of whole peeled and diced tomatoes between two consecutive growing years.     

Tomato quality is more dependent on temperature than on photosynthetically active radiation

BACKGROUND: A greenhouse experiment was performed to study the effect of cumulative air temperature and photosynthetically active radiation (PAR) on tomato quality. Tomato plants were subjected to two different shading treatments causing a 30 and 50% reduction in incoming PAR respectively (plants were exposed to 70 and 50% of incoming PAR respectively). Control plants (exposed to 100% of incoming PAR) were also included in the experiment. The experiment was carried out under unheated greenhouse conditions. To minimise the dependence of temperature on PAR, only a small area inside a large greenhouse was shaded, thereby allowing air currents to homogenise temperature all over the enclosure. Parameters of tomato quality were correlated with cumulative temperature (T_cum) and cumulative PAR (PAR_cum) for a period of 45 days before harvest. RESULTS: T_cum was strongly correlated with firmness, electrical conductivity, soluble solids content and total phenolic compounds and weakly correlated with pH, dry weight, titratable acidity and vitamin C content. PAR_cum was only weakly correlated with firmness, dry weight, soluble solids content and total phenolic compounds. CONCLUSION: T_cum has a stronger influence on tomato quality than PAR_cum. Growers could obtain tomatoes of similar quality under lower PAR than that provided by natural sunlight. Copyright © 2007 Society of Chemical Industry     

Development of cold plasma pretreatment for improving phenolics extractability from tomato pomace

In this study, high voltage atmospheric cold plasma (HVACP) with different working gases (air, Ar, He and N₂) was used to modify the surface of tomato pomace, aiming to facilitate the migration of phenolic compounds during extraction hence increase their extraction efficiency. In addition to rupturing the epidermal cells of tomato pomace, HVACP treatments were found to decrease the water contact angle of tomato peels and accelerate the drying of tomato fruit, indicating that the treated surfaces were more hydrophilic. Tomato pomace treated by He and N₂ plasmas showed increased extraction yields of phenolic compounds by nearly 10%, and all HVACP treatments increased the antioxidant capacity of tomato pomace extracts and slightly changed the concentration profile of their phenolic compounds. The developed HVACP pretreatment technology is a promising method for valorizing tomato processing byproducts with high nutritional values.Industrial relevanceTomato pomace is a good source of phenolic compounds, however, the huge amount generated from commercial tomato processing has caused a severe waste problem. Conventional extraction methods for phenolic compounds are generally time-consuming with intensive use of organic solvents that are thus considered not environment-friendly. This new cold plasma pretreatment method can not only help mitigate the environmental burdens associated with agricultural waste management but also convert waste into value-added functional food ingredients and neutraceuticals in a more efficient way.     

EFFECTS OF ACIDIFICATION ON PE ACTIVITY, COLOR AND ANTIOXIDANT PROPERTIES OF COLD BREAK TOMATO JUICE

ABSTRACT

Turbidity maintenance, high antioxidant activity and attractive red color are important attributes of good tomato juice. Acidification was found effective in pectin esterase (PE) inactivation and turbidity maintenance. However, no information related to the changes of antioxidant properties after enzyme inactivation by acidification has been reported. In this article, acidification of cold break tomato juice to pH 2 or 3 was conducted after extraction. The changes of antioxidant properties (content and activity) and their correlation with PE activity and color in the juice were studied. Results indicated that acidification enhanced the viscosity of tomato juice by decreasing its PE activity. Significant increases of the main antioxidant contents (lycopene, polyphenols and vitamin C) and antioxidant activities (1,1‐diphenyl‐2‐picrylhydrazyl scavenging, ferrous ion chelating ability [FICA] and reducing power), as well as red color, were also found. In addition, the acidified cold break tomato juice exhibited better FICA and reducing power than butylated hydroxyanisole andα‐tocopherol. This finding reveals the possibility of producing tomato juice with high antioxidant capacities by acidification.

PRACTICAL APPLICATIONS

The consumers' demand for healthy products with high quality toward fresh and health has increased remarkably these years. Tomato is one of the most popular vegetable juices, and its important quality aspects are color, stability and antioxidant capacity. Pectin esterase is the principal agent responsible for tomato juice stability. In addition, the goal of tomato juice processors is to optimize processing conditions by prevention of heat and oxidative damages on antioxidant components. Our results indicated that acidification may stabilize tomato juice and improve its color characteristics and main nutritional factors. Therefore, the acidification treatment could be used as a tool for providing the attractive color and enhancing the nutritional value and health‐promoting properties of cold break tomato juice.     

CAN WE PREDICT PEELING PERFORMANCE OF PROCESSING TOMATOES?

Tomato processors are increasingly interested in being able to predict whether tomatoes will peel well, and therefore, yield high‐value processed tomatoes. We describe two statistical models for peeling applied to multiple years of data. One model is appropriate for perfect or defect‐free tomatoes, and the second model is valid for the normal population of tomatoes obtained following mechanical harvesting. The ability to peel perfect tomatoes was significantly affected by exposure of tomatoes to temperatures greater than 100F, by fruit weight and by pericarp wall thickness. The peelability of a normal population of tomatoes was influenced by tomato weight and width as well as degree‐days and exposure to temperatures greater than 90F. Thickness of the pericarp walls and red layer positively affected the peelability of normal tomatoes. The ability to predict tomato peelability using statistical models may improve the quality of processed tomatoes and may result in more efficient commercial peeling operations.