Process optimization for thermal-assisted high pressure processing of mango (Mangifera indica L.) pulp using response surface methodology

Exploring the mechanism of transformation in Acacia nilotica (Linn.) triggered by colchicine seed treatment

BACKGROUND

Acacia nilotica Linn. is a widely distributed tree known for its applications in post-harvest and medicinal horticulture. However, its seed-based growth is relatively slow. Seed is a vital component for the propagation of A. nilotica due to its cost-effectiveness, genetic diversity, and ease of handling. Colchicine, commonly used for polyploidy induction in plants, may act as a pollutant at elevated levels. Its optimal concentration for Acacia nilotica's improved growth and development has not yet been determined, and the precise mechanism underlying this phenomenon has not been established. Therefore, this study investigated the impact of optimized colchicine (0.07%) seed treatment on A. nilotica's morphological, anatomical, physiological, fluorescent, and biochemical attributes under controlled conditions, comparing it with a control.

RESULTS

Colchicine seed treatment significantly improved various plant attributes compared to control. This included increased shoot length (84.6%), root length (53.5%), shoot fresh weight (59.1%), root fresh weight (42.8%), shoot dry weight (51.5%), root dry weight (40%), fresh biomass (23.6%), stomatal size (35.9%), stomatal density (41.7%), stomatal index (51.2%), leaf thickness (11 times), leaf angle (2.4 times), photosynthetic rate (40%), water use efficiency (2.2 times), substomatal CO2 (36.6%), quantum yield of photosystem II (13.1%), proton flux (3.1 times), proton conductivity (2.3 times), linear electron flow (46.7%), enzymatic activities of catalase (25%), superoxide dismutase (33%), peroxidase (13.5%), and ascorbate peroxidase (28%), 2,2-diphenyl-1-picrylhydrazyl-radical scavenging activities(23%), total antioxidant capacity (59%), total phenolic (23%), and flavonoid content (37%) with less number of days to 80% germination (57.1%), transpiration rate (53.9%), stomatal conductance (67.1%), non-photochemical quenching (82.8%), non-regulatory energy dissipation (24.3%), and H2O2 (25%) and O-2 levels (30%).

CONCLUSION

These findings elucidate the intricate mechanism behind the morphological, anatomical, physiological, fluorescent, and biochemical transformative effects of colchicine seed treatment on Acacia nilotica Linn. and offer valuable insights for quick production of A. nilotica's plants with modification and enhancement from seeds through an eco-friendly approach.

Application of Plant-Based Edible Coatings and Extracts Influences the Postharvest Quality and Shelf Life Potential of "Surahi" Guava Fruits

Guava fruits have a short shelf life due to climacteric nature. The current work was conducted to extend the shelf life of guavas with garlic extract (GRE), ginger extract (GNE), gum arabic (GA), and Aloe vera (AV) gel coatings. After coating, fruits of guava were stored at 25 ± 3 °C and RH 85 ± 2% for 15 days. Results showed that guavas treated with plant-based edible coatings and extracts had lower weight loss than that of the control. GRE-treated guavas had the maximum shelf life in contrast to all other treatments including the control. GNE-treated guavas showed the lowest nonreducing sugar content, whereas they had higher antioxidant activity, vitamin C content, and total phenolics compared with all other coating treatments. After the control, antioxidant capacity was the highest in GNE- and GRE-treated fruits. On the other hand, GA-treated guavas had reduced total soluble solids and juice pH (more acidic) and exhibited higher total flavonoids compared with the control, while both GA- and GNE-treated guavas had the highest flavonoid content. GRE-treated fruits exhibited the highest total sugar content and taste and aroma scores. In conclusion, GRE treatment was more effective in conserving the quality and extending the shelf life of guava fruits.

Microbial inactivation and quality impact assessment of red pepper paste treated by high pressure processing

The study aimed to investigate inactivation of naturally occurring microorganisms and quality of red pepper paste treated by high pressure processing (HPP). Central composite rotatable design was employed to determine the impacts of pressure (100-600 MPa) and holding time (30-600 s). HPP at 527 MPa for 517 s reduced aerobic mesophilic bacteria count by 4.5 log CFU/g. Yeasts and molds counts were reduced to 1 log CFU/g at 600 MPa for 315 s. Total phenols, carotenoids and antioxidants activity ranged from 0.28 to 0.33 g GAE/100 g, 96.0-98.4 mg βc/100 g and 8.70-8.95 μmol TE/g, respectively. Increase (2.5-6.7%) in these variables was observed with increasing pressure and holding time. Total color difference (ΔE∗) values (0.2-2.8) were within the ranges of 'imperceptible' to 'noticeable'. Experimental results were fitted satisfactorily into quadratic model with higher R² values (0.8619-0.9863). Optimization process suggested treatment of red pepper paste at 536 MPa for 125 s for maximum desirability (0.622). Validation experiments confirmed comparable percentage of relative errors. Overall, this technique could be considered as an efficient treatment for the inactivation of microorganisms that naturally occur in red pepper paste with minimal changes in its characteristics.

Effect of Hurdle Approaches Using Conventional and Moderate Thermal Processing Technologies for Microbial Inactivation in Fruit and Vegetable Products

Thermal processing of packaged fruit and vegetable products is targeted at eliminating microbial contaminants (related to spoilage or pathogenicity) and extending shelf life using microbial inactivation or/and by reducing enzymatic activity in the food. The conventional process of thermal processing involves sterilization (canning and retorting) and pasteurization. The parameters used to design the thermal processing regime depend on the time (minutes) required to eliminate a known population of bacteria in a given food matrix under specified conditions. However, due to the effect of thermal exposure on the sensitive nutrients such as vitamins or bioactive compounds present in fruits and vegetables, alternative technologies and their combinations are required to minimize nutrient loss. The novel moderate thermal regimes aim to eliminate bacterial contaminants while retaining nutritional quality. This review focuses on the “thermal” processing regimes for fruit and vegetable products, including conventional sterilization and pasteurization as well as mild to moderate thermal techniques such as pressure-assisted thermal sterilization (PATS), microwave-assisted thermal sterilization (MATS) and pulsed electric field (PEF) in combination with thermal treatment as a hurdle approach or a combined regime.

Irrigation water of different sources affects fruit quality attributes and heavy metals contents of un-grafted and commercial mango cultivars

In peri-urban areas, waste water is used to irrigate orchards due to scarcity of fresh water which increases heavy metals contents in soils, leaves and fruits. Due to excessive waste water irrigations, heavy metals enter into the food chain, which eventually causes metabolic disorders in humans. The present study was envisaged to investigate the effects of canal, tubewell and sewage water on the quality of mango fruits and heavy metals accumulation in soils, leaves and fruits. Leaf and fruit samples from an un-grafted (Desi mango) and six commercial cultivars of mango (Anwar Rataul, Aman Dusehri, Sufaid Chaunsa, Samar Bahisht Chaunsa, Kala Chaunsa and Anwar Rataul Late) grafted on Desi mango were collected from different mango orchards located in peri-urban areas of Multan (Pakistan) and analyzed for some physico-chemical attributes and heavy metals contents. Soil samples were also taken from these orchards irrigated with different water sources to assess the soils' heavy metals status. A significant variation was observed among the mango cultivars for their physico-chemical attributes. Sewage water irrigation improved total soluble solids (TSS), titratable acidity, ascorbic acid content, total phenolics, total carotenoids, total flavonoids and antioxidant activity of mango fruits. However, it did not affect fruit weight and shelf life. Among the heavy metals, copper and nickel contents were found in greater amounts in soils, leaves and fruits of sewage water irrigated orchards than canal and tubewell water irrigated ones. However, zinc and cadmium were not detected in any soil, water, leaf or fruit sample. The interaction among the sources of irrigation and the mango cultivars was significant for copper accumulation in different soil layers, copper and nickel accumulation in leaves of different mango cultivars, and fruit weight, titratable acidity, ascorbic acid content, total flavonoids and shelf life of mango fruits.

Influence of frying parameters and optimization of deep fat frying conditions on the physicochemical and textural properties of chicken nuggets from FUNAAB-Alpha broilers

Abstract

Influence of deep fat frying parameters on quality attributes of chicken nuggets from FUNAAB-Alpha broilers and optimization of the process using Box-Behnken experimental design of response surface methodology was investigated. Fried chicken nuggets were obtained using frying temperature (155–175 °C), frying time (3–7 min) and sample thickness (0.5–2.5 cm) as independent variables. Oil and moisture contents, texture (hardness, chewiness, adhesiveness, cohesiveness and springiness) and colour (L*, a* and b*) of samples were analyzed using standard procedures. Significance of each term in polynomial regression equations was evaluated on quality attributes. The accuracy of the regression models varied between 0.727 and 0.939. The effect of frying temperature on quality attributes of fried chicken nuggets was more significant (p > 0.05). The optimum frying temperature, frying time and sample thickness are determined as 175 °C, 3 min, 2.32 cm, respectively. Absolute percent error between optimized and experimental data were within the acceptable limit.

Graphic abstract

Optimization of the Steam Explosion Pretreatment Effect on Total Flavonoids Content and Antioxidative Activity of Seabuckthom Pomace by Response Surface Methodology

Steam explosion pretreatment was conducted on seabuckthom pomace. Response surface methodology was used to optimize the treatment conditions of steam explosion, including steam pressure, duration and particle size. After this, the content of total flavonoids and the antioxidant capacity of total flavonoids were investigated. Results showed that when the steam pressure was 2.0 MPa, duration was 88 s and a sieving mesh size was 60, the total flavonoids content in seabuckthorm reached a maximum of 24.74 ± 0.71 mg CAE/g, an increase of 246% compared with that without steam explosion treatment (7.14 ± 0.42 mg CAE/g). Also, DPPH and ·OH free radical scavenging ability showed significant improvement, with an IC₅₀ decrease to 13.53 μg/mL and 4.32 μg/mL, respectively, far lower than that in original samples. Through the scanning electron microscope, the surface of seabuckthom pomace after steam explosion was crinkled, curly, and holey. Our study showed that the content of total flavonoids in seabuckthom pomace could be obviously promoted and the antioxidant capacity of total flavonoids also improved significantly, after applying steam explosion pretreatment to seabuckthom pomace, making this approach meaningful for the reuse of seabuckthom pomace resources.

Comparative analysis of thermal-assisted high pressure and thermally processed mango pulp: Influence of processing, packaging, and storage

Storage stability and shelf-life of mango pulp packed in three different packaging films and processed using an optimized thermal-assisted high pressure processing treatment 'HPP' (600 MPa/52 ℃/10 min) was analyzed during refrigerated (5 ℃) and accelerated (37 ℃) storage and compared with the conventional thermal treatment 'TT' (0.1 MPa/95 ℃/15 min). After processing, HPP resulted in relatively lower total color difference (3.5), retained higher ascorbic acid (95%), total phenolics (106%), total flavonoids content (118%) in mango pulp compared to TT, with values of 5.0, 62, 83, 73%, respectively. However, HPP led to ∼50% enzymes inactivation (pectin methylesterase, polyphenol oxidase, peroxidase) in comparison to >90% obtained during TT. Both HPP and TT resulted in > 5 log₁₀ units reduction of the studied microorganisms to give a safe product. In contrast to the refrigerated storage, quality changes under accelerated conditions were found to be considerably rapid and dependent on packaging material irrespective of the method of processing. Shelf-life under refrigeration was limited by microbial growth and sensory quality; whereas, browning restricted the shelf-life during accelerated storage. HPP in aluminum-based retort pouch was adjudged superior processing -packaging combination for maximizing the shelf-life of mango pulp to 120 and 58 days during refrigerated and accelerated storage, respectively. In comparison, TT led to higher quality changes upon processing than HPP and resulted in shelf-life of 110 and 58 days under the same packaging and storage conditions, respectively.

The Effect of High Pressure Techniques on the Stability of Anthocyanins in Fruit and Vegetables

Anthocyanins are a group of phenolic compounds responsible for red, blue and violet colouration of many fruits, vegetables and flowers. The high content of these pigments is important as it influences directly their health promoting properties as well as the sensory quality of the product; however they are prone to degradation by, inter alia, elevated temperature and tissue enzymes. The traditional thermal methods of food preservation cause significant losses of these pigments. Thus, novel non-thermal techniques such as high pressure processing, high pressure carbon dioxide and high pressure homogenization are under consideration. In this review, the authors attempted to summarize the current knowledge of the impact of high pressure techniques on the stability of anthocyanins during processing and storage of fruit and vegetable products. Furthermore, the effect of the activity of enzymes involved in the degradation of these compounds has been described. The conclusions including comparisons of pressure-based methods with high temperature preservation techniques were presented.