Prickly Pear Fruit Research Articles

Review: Molecular analysis in prickly pear ripening: An overview

In Mexico, nopal is grown for production of prickly pear fruits takes over several thousands of hectares. This crop has been associated with the local culture since the prehispanic age, and its demand has increased in recent years due to its remarkable nutraceutical potential and its content of some key nutrients such as calcium, iron, and vitamin C, among others. The economical value of the fruit as an export product is increasing and is also becoming a very important alternative for the people who live in the production areas. However, this fruit still has undesirable characteristics such as the high number of spines and seeds in its fruits and a poor post-harvest life that limits the production and consumer acceptance. At ripening, the fruit undergoes many changes, including the development of color and aroma and improvements in flavor and texture, that make them attractive to potential consumers. Ripening is considered the main process in fruit development, and studies focused on this process have inc...

Response surface modeling and optimization of process parameters for aqueous extraction of pigments from prickly pear (Opuntia ficus-indica) fruit

The objectives of this study are to determine the optimum conditions for the aqueous extraction of pigments from prickly pear fruit using a three-level three-factor Box–Behnken design under response surface methodology. Pigments were extracted from prickly pears using water as solvent at different extraction temperature (30–50 °C), time (20–120 min) and mass of fruit (0.5–1.5 g). The experimental data obtained were analyzed by Pareto analysis of variance (ANOVA) and fitted to a second-order polynomial equation using multiple regression analysis. An optimization study using Derringer's desired function methodology was performed and the optimal conditions based on both individual and combinations of all responses (extraction temperature of 40 °C, time of 115 min and mass of 1.44 g) were determined. At this optimum condition, the total betacyanin and betaxanthin content were found to be 13.4354 mg/100 g and 24.2922 mg/100 g with desirability value of 0.917. The experimental values agreed with those predicted values.

Chemical Cues Influence Pupation Behavior of Drosophila simulans and Drosophila buzzatii in Nature and in the Laboratory

In the wild, larvae of several species of Drosophila develop in heterogeneous and rapidly changing environments sharing resources as food and space. In this scenario, sensory systems contribute to detect, localize and recognize congeners and heterospecifics, and provide information about the availability of food and chemical features of environments where animals live. We investigated the behavior of D. simulans and D. buzzatii larvae to chemicals emitted by conspecific and heterospecific larvae. Our goal was to understand the role of these substances in the selection of pupation sites in the two species that cohabit within decaying prickly pear fruits (Opuntia ficus-indica). In these breeding sites, larvae of D. simulans and D. buzzatii detect larvae of the other species changing their pupation site preferences. Larvae of the two species pupated in the part of the fruit containing no or few heterospecifics, and spent a longer time in/on spots marked by conspecifics rather than heterospecifics. In contrast, larvae of the two species reared in isolation from conspecifics pupated randomly over the substrate and spent a similar amount of time on spots marked by conspecifics and by heterospecifics. Our results indicate that early chemically-based experience with conspecific larvae is critical for the selection of the pupation sites in D. simulans and D. buzzatii, and that pupation site preferences of Drosophila larvae depend on species-specific chemical cues. These preferences can be modulate by the presence of larvae of the same or another species.

Purification and characterization of an amylase from Opuntiaficus‐indica seeds

In Tunisia, prickly pear fruit grow spontaneously; it is consumed as fresh fruit, juice or jam. When the fruit is used for juice production, the seeds are discarded and go to waste. Our study aimed to extract biomolecules from seeds by producing value-added products from the fruits. An amylase from Opuntia ficus-indica seeds was extracted and purified to homogeneity. An increase in specific activity of 113-fold was observed. The apparent molecular mass of the enzyme is 64 kDa. The optimum pH and temperature for enzyme activity were pH 5 and 60 °C, respectively. Under these conditions, the specific activity is 245.5 U mg(-1) . The enzyme was activated by Co(2+) and Mg(2+) (relative activity 117% and 113% respectively) at lower ion concentrations. It was strongly inhibited by Mn(2+) and Fe(2+) . Cu(2+) inhibited totally the activity of this enzyme, but Ca(2+) has an inhibitory effect which increases with ion concentration. The extracted enzyme belongs to the exo type of amylases and is classified as a β-cyclodextrin glycosyltransferase since it generates mainly β-cyclodextrin from starch. It exhibits high thermal stability and a broad range of pH stability, making it a promising prospect for industrial and food applications.

Female White-Tailed Deer Body Condition and Diet After a Large Spring Wildfire

Abstract Frequency of large rangeland wildfires may increase in the southwestern United States and northeastern Mexico as a result of exotic grass invasion and reduced emphasis on livestock production, but effects of such fires on white-tailed deer ( Odocoileus virginianus ) are poorly documented. A large wildfire burned s 90% of the 6 151-ha Chaparral Wildlife Management Area in southern Texas during March 2008, creating an opportunity to study short-term effects of wildfire on white-tailed deer food habits, body condition, and pregnancy. We harvested 26 female deer between 7 April and 20 June 2008 and recorded dressed body weight, body condition, number of corpora lutea, and number and size of fetuses. We used rumen contents to quantify forage classes consumed. Deer ate prickly pear ( Opuntia engelmannii ) pads and emergent grasses during April and shifted to forbs and browse as vegetation communities recovered. Deer consumed mesquite ( Prosopis glandulosa ) beans and prickly pear fruit during mid-June. Body condition measures did not vary during the collection period, suggesting deer were able to acquire sufficient nutrients to meet requirements. Fetal development rate appeared normal. Precipitation (11.4 cm) during late April and May probably allowed vegetation to recover from the wildfire. White-tailed deer are resilient opportunists and were able to maintain body condition and pregnancy after a large-scale wildfire.

Anthocyanins and betalains as light-harvesting pigments for dye-sensitized solar cells

We present the photoelectrochemical properties of dye-sensitized solar cells using natural pigments containing betalains and anthocyanins as sensitizers. The dyes extracted from grape, mulberry, blackberry, red Sicilian orange, Sicilian prickly pear, eggplant and radicchio have shown a monochromatic incident photon to current efficiency (IPCE) ranging from 40% to 69%. Short circuit photocurrent densities (Jsc) up to 8.8mA/cm2, and open circuit voltage (Voc) ranging from 316 to 419mV, were obtained from these natural dyes under 100mW/cm2 (AM 1.5) simulated sunlight. The best solar conversion efficiency of 2.06% was achieved with Sicilian prickly pear fruits extract. The influence of pH and co-absorbers on natural sensitizers, were investigated and discussed.

Phytotherapy of Alcoholism

Alcoholism is a medical, social, and economic problem where treatment methods mostly include difficult and long-lasting psychotherapy and, in some cases, quite controversial pharmacological approaches. A number of medicinal plants and pure natural compounds are reported to have preventive and therapeutic effects on alcoholism and alcohol dependency, but their constituents, efficacy and mechanism of action are mostly unknown so far. Recently, kudzu [Pueraria lobata (Willd.) Ohwi], St. John's wort (Hypericum perforatum L.), danshen (Salvia miltiorrhiza Bge.), ginseng (Panax ginseng C.A. Mey.), Japanese raisin tree (Hovenia dulcis Thunb.), ibogaine (Tabernanthe iboga H. Bn.), evening primrose (Oenothera biennis L.), prickly pear fruit (Opuntia ficus indica (L.) Mill.), purple passionflower (Passiflora incarnata L.), thyme (Thymus vulgaris L.), fenugreek seed (Trigonella foenum-graecum L.), ginger (Zingiber officinale Roscoe) and many others drew the attention of researchers. Can, therefore, drugs of natural origin be helpful in the treatment of alcoholism or in decreasing alcohol consumption?

Assessing diet and seasonality in the Lower Pecos canyonlands: an evaluation of coprolite specimens as records of individual dietary decisions

This article presents an evaluation of coprolite specimens from the Lower Pecos canyonlands as records of individual dietary decisions. Prior studies of coprolites from this region have greatly expanded our knowledge of Archaic subsistence patterns, but have not taken full advantage of the record of individual dietary decisions recorded in each coprolite specimen. The menu, or dietary combinations, reflected in individual coprolite specimens are assessed through the identification of several congruent botanical components derived from the same food resource, phytoliths, fiber ultimates, and epidermal sheets. The data is analyzed with hierarchical cluster analysis, an exploratory statistical technique. The resultant menus reflected in these clusters are evaluated with reference to a diet-breadth model developed for the known staple resources of the canyonlands. Three main menus are apparent in the specimens. The first menu consists of prickly pear ( Opuntia sp.) cladodes, or nopales, and was principally, although not exclusively, consumed in the late spring. This menu is primarily consumed when other resources were not readily available and may be considered a dependable but undesirable meal. The second menu consists of pit-baked lechuguilla ( Agave lechuguilla) and sotol (Dasylirion sp.) caudices, or hearts, common throughout the cool season. This menu entails high processing costs, but would provide a reliable caloric return. The third menu exhibits a monolithic reliance on prickly pear fruits, or tunas, during the summer. The ease of harvest and consumption is reflected in the seasonal dominance of this resource, which was assuredly a highly desirable meal. The dietary patterns recorded in the coprolite specimens from the Lower Pecos canyonlands demonstrate a seasonally variable diet-breadth that incorporated low-ranked resources during times of seasonal scarcity as well as a monolithic dependence on high-ranked resources when they were available in the local landscape.

Formulación de una mermelada a partir de pulpa y cáscara de tunas (Opuntia spp.) elaborada a nivel planta piloto

Después de una serie de pruebas experimentales de mermeladas a base de pulpa y cás­cara de tunas a nivel laboratorio, generados de proyectos de investigación anteriores, y con base en resultados de evaluación sensorial, análisis microbiológico y fisicoquímico, se seleccionó una formulación de mermelada a partir de una mezcla de pulpa y cáscara de tuna variedad reyna, y pulpa de tuna variedad xoconostle para su procesamiento a nivel planta piloto. La mermelada elaborada fue caracterizada mediante análisis fisicoquímico y microbiológico. Dentro de los análisis fisicoquímicos se incluyó la determinación de Fibra Dietética (4.35 g de fibra dietética/15 g de mermelada), siendo éste uno de los análisis más importantes, cuyo valor procede principalmente de la cáscara de las tunas. Basados en las especificaciones exigidas por la Norma Oficial Mexicana, el producto puede considerarse apto para su consumo y para propósitos de comercialización.

English

  In Mexico in the region of Nopaltepec in Mexico State, the edible Cactus crop, Opuntia ficus-indica is mainly cultivated for prickly pear fruit production. This crop has problems with common pests (insects, mollusks and weeds) which may serve as reservoirs and together with the named Cactus with phytoplasma-like symptoms which through the time inhibit the fruit production, and for this reason, the farmers called these Opuntia plants as Planta Macho (male plant). For molecular identification of the probably involved phytoplasma during 2005 and 2006, 38 samples of Opuntia plant tissues, fruit and some pests were collected for DNA extraction. By direct and nested PCR, 16S rRNA gene was amplified and sequenced. PCR products were analyzed by RFLP with restriction  enzymes and in the sequences restriction sites were mapped. Phylogenetic analysis showed that the same phytoplasma was associated with Opuntia crop and its pests (the weeds Argemone mexicana, a grass and Lupinus sp.; a chinch bugs, Chelinidea sp. and the brown garden snail, Helix aspersa). Thus the edible Cactus crop and pests represented novel hosts of Cactus male plant Phytoplasma, and was classified as 16SrI Aster yellows group, of the species Candidatus phytoplasma asteris. This is the first report of this phytoplasma in Mexico and elsewhere.      Key words: Argemone, brown garden snail, chinch bugs, edible Cactus, grasses,Lupinus, male plant phytoplasma, Mexico.

Extraction and determination of polyphenols and betalain pigments in the Moroccan Prickly pear fruits (Opuntia ficus indica)

Polyphenols and betalain pigments respond property’s antioxidants benefic for the human health (Will Strike et al., 2002; Lecerf, 1999). The item present shows procured results for strengths in polyphenols and in betalains to the time in fruits and in their juice for the period 2008–2009. Our searches show that rate in polyphenols is more increased in the entire fruit than in only the juice. We have equally remarked that the red prickly pear contains amounts of polyphenols more raised than those of the yellow variety.This study has permitted us equally to value betalain pigments extracted from fruity juice. These are the betalains present in the epidermis and the pulp of the prickly pear confers on it its color varying from yellow to purple. Results show that yellow and red prickly pears contain imported strengths in betalains. Our work shows that the red prickly pear contains betaxanthin pigments in excess of the indicaxanthin that permits to valorize human’s potential spring of genuine colorings. Betalains and polyphenols are antioxidants that contribute to nutritional prickly pears’ quality and to their products of transformation.

Biofunctional activity of tortillas and bars enhanced with nopal. Preliminary assessment of functional effect after intake on the oxidative status in healthy volunteers

BackgroundPrickly pear cactus stem (nopal) has been used in folk medicine and a raw material since ancient times. Stems have been proved to possess components with valuable biological activities: anti inflamatory, antioxidant, antiulcerogenic, hypoglycemic, and so forth. Nowadays, people consume foods not only to cover the nutritional requirements, they also demand for healty, natural and convenient foods that show biological activity. This study evaluated the bio-functional effects of consuming tortillas or bars (filled with prickly pear fruit jam) supplemented or not with nopal dietary fiber.ResultsThe addition of nopal increased the fiber and polyphenols content in both tortillas (16.67%, 2.33 mg QE/L) and bars (13.79%, 1.99 mg QE/L). Furthermore the trolox equivalent antioxidant capacity (TEAC, 1.47 mmol/L), polyphenols (7.67 mg QE/L) and vitamin C (77.91 μmol/L) showed increased levels in volunteer's plasma after intake. Also lower levels of glucose (4.43 mmol/L), total cholesterol (4.27 mmol/L), LDL (1.96 mmol/L) and triglycerides (1.54 mmol/L) were observed in plasma after the supplementation scheme with nopal-based tortilla, while GSH:GSSG ratio in erythrocytes was higher.ConclusionsThe results suggested that the intake of nopal-based tortillas with high content in fiber and antioxidant compounds can help to improve the overall oxidative status in healthy humans, which can reduce the risk of some chronic diseases. In addition, these products showed suitable physicochemical characteristics to be marketed.

IDENTIFICATION AND QUANTIFICATION OF PIGMENTS IN PRICKLY PEAR FRUIT

Identification and quantification of betalains in ten cultivars/lines of prickly pear (Opuntia spp.) fruit were conducted with reverse phase high-performance liquid chromatography-diode array detection (HPLC-DAD) coupled with electrospray mass spectrometry (ESI-MS). Betacyanins and betaxanthins were identified by comparison with the UV/Vis and mass spectrometric characteristics as well as the retention times of semi-synthesized reference betaxanthins. Carotenoids and chlorophylls were also identified and quantified based on their molecular mass determined by applying HPLC-DAD coupled with Positive Atmospheric Pressure Chemical Ionization Mass Spectrometry (APCI-MS). A total of 24 known/unknown betalains were present in the studied prickly pear fruit, including 18 betaxanthins and 6 betacyanins. The ratio and concentration of betalain pigments are responsible for the color in the different cultivars, showing the highest betalains content in fruit of purple color, comparable to that found in red beet (Beta vulgaris L. 'Pablo'). All cultivars/lines had a similar carotenoid profile, in which lutein was the most abundant compound in 'Camuesa', while neoxanthin was the most abundant compound in '21441'. Chlorophyll a was the most abundant in all cultivars/lines with the highest quantity in '21441'. To our knowledge, this is the first time that separation of carotenoids and chlorophylls has been reported in cactus pear fruit using mass spectroscopy. Our results indicate that prickly pear fruit can be considered as a potential source of yellow and red natural colorants.

THE CORRELATION BETWEEN SOME NUTRITIONAL COMPONENTS WITH TOTAL ANTIOXIDANT CAPACITY (MEASURED WITH SIX DIFFERENT ASSAYS) IN EIGHT HORTICULTURAL COMMODITIES

The contents of total soluble phenolics (TSP), vitamin C, vitamin E, β-carotene and total carotenoids (TC) in eight fruits have been correlated with the antioxidant capacity (AC) of hydrophilic and lipophilic extracts measured by six different antioxidant assays (DMPD, DPPH, FRAP, ORAC, TEAC, TOSC). Guava had the highest TSP content, followed by black sapote, strawberry, prickly pear cladodes (nopal), avocado, prickly pear fruit, and papaya. Guava fruit had the highest vitamin C content, whereas the lower levels were found in black sapote and nopal. Ascorbic acid was the main contributor to the total vitamin C content (>85%), with exception of nopal and avocado. Evaluated fruits showed significant differences in vitamin E content, with the exception of mango and strawberry, without differences between them, and the highest content was in black sapote, followed by avocado, guava, nopal, mango, strawberry, papaya and prickly pear fruit. Mango had the highest β-carotene and TC, and prickly pear fruit, guava, and strawberry had the lowest TC. In relation with AC, values of hydrophilic extracts ranged from 78.9 to 6230.6 mmol of trolox equivalents (TE)/100 g with DPPH assay; 798.4 to 15420.4 mmol TE/100 g with DMPD assay; 257.1 to 7482.9 mmol TE/100 g with FRAP assay; 330.4 to 8591 mmol TE/100 g with ORAC assay; 222.1 to 2243.8 mmol TE/100 g with TEAC assay; and from 2055.5 to 8235.6 mmol TE/100 g with TOSC assay. Lipophilic values ranged from 0 to 91.2 mmol TE/100 g with DPPH assay; 0 to 145.2 mmol TE/100 g with DMPD assay; 8.4 to 31.8 mmol TE/100 g with TEAC assay; and from 13.7 to 61 mmol TE/100 g with TOSC assay. In general, lipophilic values were <5% of the hydrophilic values except for a very few samples. The hydrophilic extract of guava had the major value when evaluated with DMPD, DPPH, FRAP, TEAC and TOSC assays; whereas with the ORAC assay, black sapote was the major one. On the other hand, the hydrophilic extracts of papaya and prickly pear fruit presented the lowest values of AC with all used assays. Regression analysis revealed that the content of TSP and vitamin C were highly correlated with the AC of hydrophilic extracts evaluated by the six assays. On the other hand, only the AC of the lipophilic extracts, evaluated by the DMPD assay, was highly correlated with the content of β-carotene and TC.

ANTINEOPLASTIC AND ANTIOXIDANT PROPERTIES OF SOME FRUITS AND VEGETABLES USING EXPERIMENTAL MODELS OF MAMMARY CANCER

Consumption of fruits and vegetables has been associated with reduced risk of chronic diseases. They are rich in several antioxidant phytochemicals such as carotenoids and phenolic compounds that could be responsible for the health benefits. We studied the antineoplastic properties of some fruits and vegetables using in vivo and in vitro models. First, we studied the effect of ‘Ataulfo’ mango consumption on chemically-induced mammary carcinogenesis and plasma antioxidant capacity (AC) in rats treated with the carcinogen N-methyl-Nnitrosourea (MNU). Mango was administered in the drinking water (0.02-0.06 g/ml) during both short-term and long-term periods to rats, and plasma antioxidant capacity was measured by ferric reducing/antioxidant power (FRAP) and total oxyradical scavenging capacity assays. Mango consumption did not have an effect on mammary carcinogenesis (incidence, latency and number of tumors), nor on plasma AC of rats treated with MNU. Second, we screened using methylthiazolydiphenyltetrazolium bromide assay the antiproliferative activity of aqueous extracts of avocado, black sapote, guava, mango, cactus cladodes (cooked and raw), papaya, pineapple, four different prickly pear fruit, grapes and tomato, on the breast cancer cell line MCF-7. β-carotene, gallic acid, total phenolic contents and AC were analyzed in each aqueous extract. In vitro study showed that only the papaya extract had a significant antiproliferative effect and we did not notice a relationship between total phenolic content and AC with antiproliferative effect. These results suggested that each plant food has a unique combination in quantity and quality of phytochemicals which could determine its biological activity.

Purification and characterisation of a soluble nucleotide pyrophosphatase/phosphodiesterase from prickly pear (Opuntia ficus indica) fruits

A glycosylated metallo-protein, nucleotide pyrophosphatase/phosphodiesterase, in a soluble form was purified to homogeneity from prickly pear (Opuntia ficus indica) fruits. The native protein had a molecular mass of 105±8kDa and was formed by two apparently identical subunits each containing 1 Ca2+ and 1Mg2+ ion. The Opuntia enzyme exhibited hydrolytic activities toward pyrophosphate/phosphodiester bonds of a broad range of natural substrates, but among these, only NAD(P) and NAD(P)H were hydrolysed very efficiently. Moreover, Opuntia pyrophosphatase/phosphodiesterase hydrolysed the artificial substrate thymidine 5′-monophosphate 4-nitrophenyl ester, whereas it did not show any catalytic activity toward bis-4-nitrophenyl phosphate, which is a substrate of other pyrophosphatase/phosphodiesterase enzymes. We observed an increase of enzyme activity from the green to the red stage of fruits development, suggesting that ONPP activity might be related to the ripening of prickly pears. The protein was shown to be resistant to 75°C for 30min. Other biochemical characteristics were investigated and are reported here.

Modelling of the Drying Kinetics of Opuntia Ficus Indica Fruits and Cladodes

The effect of the drying rates of fruit and cladode of Opuntia Ficus Indica was examined at different temperatures. The experimental drying curves show only a falling drying rate period. The values of drying rate of prickly pear (fruit and cladode) almost doubled when the drying temperature was increased from 40 to 60°C. The experimental drying data were applied to various drying equation (Logarithmic; Wang and Singh, Henderson and Pabis, MMF model and Midilli equation). Midilli equation was optimal for characterizing drying behaviour of prickly pear for the whole range of temperature with a correlation coefficient of 99.99% for the fruit and the cladode and a standard error of 0.0015 for the fruit and 0.0017 for the cladode.

LIPOXYGENASE ACTIVITY IN PRICKLY PEAR FRUIT (OPUNTIA FICUS INDICA[L.] MILL. CACTACEAE)

ABSTRACT Prickly pear LOX activity was detected in the membrane fractions of the fruit extracts at various stages of ripening. LOX specific activity was very low in the fruit of wild plants at the green stage (0.49 ± 0.04) and increased with fruit ripening, more than doubling in the ripened fruit (1.22 ± 0.06). Moreover, it was not influenced by the cultivar, whereas it was considerably increased (13.3 ± 1.4) by agronomic processes to which prickly pear plants are submitted to improve the organoleptic properties of fruits. The apparent molecular mass of the enzyme was estimated to be 96 kDa. The enzyme had an optimum pH value of 5.5 and a clear specificity for linolenic acid, which was oxidized at a rate one and a half times that of linoleic acid, under the same reaction conditions. The involvement of prickly pear LOX in the flavor biosynthesis of the fruit is supposed. PRACTICAL APPLICATIONS Over the last decade in particular, prickly pear fruits have been widely used as food, not only the whole fruit but also processed to make juices, jams and liquors popular the world over. Prickly pear production has therefore risen considerably and consequently both the labor force employed and revenues generated have increased. For those engaged in this sector it is therefore a prime objective to maximise the profile and thereby profitability of the fruit. It is here that our research into lipoxygenase activity can play a part, as it is known that this enzyme is responsible for the organoleptic properties of fruits and vegetables. The results are presented below. The relationship between lipoxygenase specific activity and specific agronomic processes utilized to improve the fruit quality is also addressed.

Efficient Dye-Sensitized Solar Cells Using Red Turnip and Purple Wild Sicilian Prickly Pear Fruits

Dye-sensitized solar cells (DSSCs) were assembled by using the bougainvillea flowers, red turnip and the purple wild Sicilian prickly pear fruit juice extracts as natural sensitizers of TiO2 films. The yellow orange indicaxanthin and the red purple betacyanins are the main components in the cocktail of natural dyes obtained from these natural products. The best overall solar energy conversion efficiency of 1.7% was obtained, under AM 1.5 irradiation, with the red turnip extract, that showed a remarkable current density (Jsc = 9.5 mA/cm2) and a high IPCE value (65% at λ = 470 nm). Also the purple extract of the wild Sicilian prickly pear fruit showed interesting performances, with a Jsc of 9.4 mA/cm2, corresponding to a solar to electrical power conversion of 1.26%.

FIRMNESS CHANGES OF IMPREGNATED WHOLE PEELED PRICKLY PEAR

ABSTRACT The firmness of green prickly pear fruits (Opuntia ficus indica) impregnated with a sucrose isotonic solution (IS) was evaluated. Whole fresh‐peeled prickly pears were processed under different combinations of vacuum pressure (pv), vacuum application time (tv) and relaxation time (tr). Puncture test was applied to impregnated and fresh whole prickly pears. The maximum force (Fmax), average force (Fav) and the work (Wp) required to puncture 3 cm in the fruits were measured. Second order models provided good fits to the experimental data of Fmax (R2 = 0.754), Fav (R2 = 0.788) and Wp (R2 = 0.792). Impregnation factors pv, tr, tv–tr significantly affected firmness parameters (P ≤ 0.05). Firmness parameters of fresh‐peeled prickly pear were Fmax = 10.934 ± 1.571 N, Fav = 2.152 ± 0.270 N and Wp = 5.930 × 10−2 ± 0.0054 Nm. Firmness reduction of impregnated fruits was linked to the IS impregnation levels and deformation‐relaxation phenomena.PRACTICAL APPLICATIONSThe aim of this study was to assess the influence of impregnation conditions on firmness of whole peeled prickly pear, as excessive softening is the main factor limiting consumer acceptability. This study helps to identify the better impregnation conditions for maintaining firmness. This information could be useful for the application of vacuum impregnation in the development of fruits and vegetables products, in which the impregnating solution is used as a carrier of active agents. To date, very limited studies have been conducted in whole fruits involving only peeling and impregnation operations.