Quality evaluation of minimally fresh-cut processed pineapples

Kinetic models applied to quality change and shelf-life prediction of fresh-cut pineapple in food cold chain

This study developed a predictive model of the remaining shelf-life of fresh-cut pineapple by considering microbial, chemical, and sensory indicators under storage temperatures.The effect of temperature on quality indices (Ea)was29.57-96.8 kJ/mol. The acceptable limits for vitamin C loss and weight loss for fresh-cut pineapple were 27.71 mg/100 g fresh weight and 4.32 %, respectively, in accordance with cutoffs determined on the basis of sensory changes. Key quality indicators that could predict the remaining shelf-life between 5 °C and 25 °C were the TVC and WL. Vitamin C loss was only suitable when storage temperature was above 10 °C. The remaining shelf-life in a real supply chain in terms of the TVC, vitamin C loss, and WL were 9.9, 3.5, and 4 days, respectively. Overall, the shelf-life prediction model developed using selected key indicators may help in managing temperature in the fresh-cut fruit supply chain and improving storage shelf-life.

Eco-safe composite edible coating of hydrocolloids with papaya leaf extract improves postharvest quality and shelf life of papaya fruit under ambient storage

Papaya postharvest management using low-temperature storage is discouraged as it is a tropical fruit. Extensive research is going on to preserve papaya quality at ambient storage using edible coatings and its composites. The present investigation examined the effects of an eco-safe composite edible coating consisting of hydrocolloid carboxymethyl cellulose (CMC) (1%), guar gum (1.5%), xanthan gum (0.3%), and Gum Arabic (10%) combined with papaya leaf extract (PLE) (1:1 ratio by volume) applied as dip treatment on "Red Lady" papaya fruit at ambient storage condition. Among all the attempted treatments, "PLE incorporated with CMC (1%)" was found to be the best, as the treated fruit exhibited the highest levels of biochemicals, whereas the lowest levels of physiological and enzymatic activity, which positively affected the shelf life. The "CMC + PLE" treatment enhanced the fruit gloss score by 70.1%, phenolics by 6.1%, ascorbic acid by 22.3%, total carotenoid content by 7.4%, and fruit predilection score by 22.0% over the control fruit. However, it lowered (controlling) the physiological loss in weight by 51.0%, decay incidence by 66.6%, and polygalacturonase and pectin methylesterase activity by 24.92% and 35.29%, respectively, over control. Moreover, this treatment exhibited the highest fruit purchase predilection score and prolonged the storage life for >3 days on the physiological loss standard basis (≤10%). This study indicates that "CMC (1%) with PLE (1:1)" composite coating application on papaya under ambient conditions might be an effective, environmentally friendly, and health-friendly way to retain the quality and extend the storage life.

Towards a Multispectral Imaging System for Spatial Mapping of Chemical Composition in Fresh-Cut Pineapple (Ananas comosus)

With increasing public demand for ready-to-eat fresh-cut fruit, the postharvest industry requires the development and adaptation of monitoring technologies to provide customers with a product of consistent quality. The fresh-cut trade of pineapples (Ananas comosus) is on the rise, favored by the sensory quality of the product and mechanization of the cutting process. In this paper, a multispectral imaging-based approach is introduced to provide distribution maps of moisture content, soluble solids content, and carotenoids content in fresh-cut pineapple. A dataset containing hyperspectral images (380-1690 nm) and reference measurements in 10 regions of interest of 60 fruit (n = 600) was prepared. Ranking and uncorrelatedness (based on ReliefF algorithm) and subset selection (based on CfsSubset algorithm) approaches were applied to find the most informative wavelengths in which bandpass optical filters or light sources are commercially available. The correlation coefficient and error metrics obtained by cross-validated multilayer perceptron neural network models indicated that the superior selected wavelengths (495, 500, 505, 1215, 1240, and 1425 nm) resulted in prediction of moisture content with R = 0.56, MAPE = 1.92%, soluble solids content with R = 0.52, MAPE = 14.72%, and carotenoids content with R = 0.63, MAPE = 43.99%. Prediction of chemical composition in each pixel of the multispectral images using the calibration models yielded spatially distributed quantification of the fruit slice, spatially varying according to the maturation of single fruitlets in the whole pineapple. Calibration models provided reliable responses spatially throughout the surface of fresh-cut pineapple slices with a constant error. According to the approach to use commercially relevant wavelengths, calibration models could be applied in classifying fruit segments in the mechanized preparation of fresh-cut produce.

Effect of Composite Edible Coatings Combined with Modified Atmosphere Packaging on the Storage Quality and Microbiological Properties of Fresh-Cut Pineapple

This study investigated the effect of edible coating (EC), modified atmosphere packaging (MAP), and edible coating + modified atmosphere packaging (EC + MAP) treatments on the quality of fresh-cut pineapples during storage at 4 °C. The quality differences were analyzed by measuring the quality, physiological indicators, and total microbial counts. After 8 d of storage, the brightness (L*) values of the EC + MAP and control samples were 72.76 and 60.83, respectively. The water loss and respiratory rate of the EC + MAP were significantly inhibited from 0% and 29.33 mg CO₂ kg^-1 h^-1 to 4.13% and 43.84 mg CO₂ kg^-1 h^-1, respectively. Furthermore, the fresh-cut pineapples treated with EC + MAP presented a good appearance, with lower total soluble solids (TSS) and relative conductivity and higher titratable acid (TA), ascorbic acid (AA), total phenol content, and firmness compared to the other treatment groups. At the end of storage, the EC + MAP samples exhibited the lowest polyphenol oxidase (PPO) activity, peroxidase (POD) activity, and malondialdehyde (MDA) content at 28.53 U, 60.37 U, and 1.47 nmol·g^-1, respectively. Furthermore, the efficiency of EC + MAP treatment exceeded that of EC or MAP alone, preventing key problems involving the surface browning and microbiological safety of the fresh-cut pineapples. The results showed that EC + MAP treatment was more successful in maintaining the storage quality and extending the shelf life of fresh-cut pineapples.

Utilisation of Deep Learning with Multimodal Data Fusion for Determination of Pineapple Quality Using Thermal Imaging

Fruit quality is an important aspect in determining the consumer preference in the supply chain. Thermal imaging was used to determine different pineapple varieties according to the physicochemical changes of the fruit by means of the deep learning method. Deep learning has gained attention in fruit classification and recognition in unimodal processing. This paper proposes a multimodal data fusion framework for the determination of pineapple quality using deep learning methods based on the feature extraction acquired from thermal imaging. Feature extraction was selected from the thermal images that provided a correlation with the quality attributes of the fruit in developing the deep learning models. Three different types of deep learning architectures, including ResNet, VGG16, and InceptionV3, were built to develop the multimodal data fusion framework for the classification of pineapple varieties based on the concatenation of multiple features extracted by the robust networks. The multimodal data fusion coupled with powerful convolutional neural network architectures can remarkably distinguish different pineapple varieties. The proposed multimodal data fusion framework provides a reliable determination of fruit quality that can improve the recognition accuracy and the model performance up to 0.9687. The effectiveness of multimodal deep learning data fusion and thermal imaging has huge potential in monitoring the real-time determination of physicochemical changes of fruit.

A preliminary study on the possibility of fermented pineapple peel residue partially replacing whole corn silage in feeding Chuanzhong black goats

This study aims to assess the effects of the partial replacement of whole corn silage (WCS) with fermented pineapple peel residue (FPPR) on growth, serological parameters, muscle quality, rumen microorganisms, and fecal microorganisms. A total of 24 Chuanzhong black goats weighing 10.23 ± 1.42 kg were evaluated in a randomized complete trial design in accordance with the following treatments: (1) 0% FPPR in the diet, (2) 25% FPPR in the diet, and (3) 50% FPPR in the diet. In goats, the partial substitution of FPPR for WCS increased the abundance of probiotics, such as Blautia, Butyrivibrio fibrisolvens, and Ruminococcus albus, and did not exert significant effects on overall serological parameters and muscle quality. In conclusion, the partial substitution of FPPR for WCS in the diet did not impair or affect the productive performance of goats.

Shelf Life Prediction and Kinetics of Quality Changes in Pineapple (Ananas comosus) Varieties at Different Storage Temperatures

Shelf life estimation is an important factor to predict the freshness of fruits. This study aimed to investigate the shelf life and the changes in the physicochemical properties of three different pineapple varieties, namely MD2, Josapine, and Morris stored at 5, 10, and 25 °C. The effect of storage temperature on pineapple changes in total soluble solids, pH, moisture content, firmness, and colour was evaluated for 21 days of the storage period. It was revealed that different storage temperatures have a significant effect on the shelf life and quality of different pineapple varieties. The firmness and moisture content showed high regression coefficients, hence were used for the shelf life prediction of pineapple based on kinetic models. By using first-order kinetics, the coefficient of determination (R2) values for quality changes in pineapples ranged from 0.893 to 0.992. The results also demonstrated that the samples stored at 10 °C had the longest shelf life in relation to the changes in firmness and moisture content of the fruit. The findings indicated that shelf life estimation plays an important role to improve the quality preservation of fresh fruits and vegetables during storage.

Comparison of Different Varieties on Quality Characteristics and Microbial Activity of Fresh-Cut Pineapple during Storage

This study compared the quality and storage characteristics of four pineapple varieties to select those displaying adequate storage resistance and those suitable for freshly cut processing. Four varieties of pineapple, namely Tainong No.16, Tainong No.17, Tainong No.11, and Bali, were used to analyze the quality differences in freshly cut pineapple during storage by measuring the quality, physiological indicators, and total microbial count. The results indicated that the nutritional quality and storability of freshly cut pineapples differed significantly among the varieties. During refrigeration at 4 °C, Tainong No.11 and Bali displayed the shortest storage period of 4 d, while Tainong No.17 and Tainong No.16 presented storage periods of 5 d and 6 d, respectively. A sensory evaluation indicated that the Tainong No.16 variety was superior in terms of consumer preference, while the Bali slices were generally rated lower than the other cultivars. Additionally, the sensory properties, weight loss, firmness, and ascorbic acid (AA) content of Tainong No.16 changed the least during storage, with values of 60.75%, 6.48%, 75.15%, and 20.44%, respectively. Overall, the quality order of the four varieties of freshly cut pineapples during storage was: Tainong No.16 > Tainong No.17 > Tainong No.11 > Bali. Moreover, two-way ANOVA showed that the main effect of variety and storage time on the storage quality of fresh-cut pineapple was significant (p < 0.05). The interaction effect of variety and storage time on other quality characteristics of fresh-cut pineapple was significant (p < 0.05) except for Titratable acid (TA) and AA. In conclusion, Tainong No.16 displayed higher storage potential than the other varieties. The results of this work provide application possibilities to promote the successful processing of pineapple cultivars as freshly cut produce.

Ferulic Acid Treatment Maintains the Quality of Fresh-Cut Taro (Colocasia esculenta) During Cold Storage

Taro (Colocasia esculenta) is a major root crop or vegetable in the world, and the corm is a good source of many nutrients including starch, vitamins, and minerals. Taro corms are processed into various forms before consumption, which makes them perishable, reduces the shelf life, and increases postharvest losses. The surface browning of fresh-cut taros is one of the major factors that limits storage life and affects consumer acceptance. In this study, the effects of ferulic acid (FA) as an effective agent in the prevention of quality deterioration were investigated. Fresh-cut taros were immersed in distilled water and different concentrations of FA (1, 2, 5, 10, and 20 mM) solutions for 30 min, air-dried at 25°C for 30 min, and then stored at 5°C for 12 days to investigate the effects of FA on browning. Among the FA concentrations tested, 10 mM resulted in significantly higher L * values, lower a * and b *, and browning index values. FA treatment (10 mM) also induced de novo biosynthesis of two volatile compounds, including non-anal and octanoic acid ethyl ester in fresh-cut taros following extended cold storage. The results suggest that FA treatment maintains the quality of fresh-cut taros under cold conditions. FA treatment enhanced PAL activity and gene expression but reduced total phenolic content and the expression of six C4H, 4CL, and CHS genes, suggesting that FA treatment reduced phenolic biosynthesis. FA treatment reduced PPO activity and gene expression and decreased soluble quinone content, suggesting that FA treatment suppressed the phenolic oxidation. FA treatment enhanced the activity and gene expression of CAT and POD, reduced those of LOX, and decreased MDA and H2O2 levels, suggesting that FA treatment activated the antioxidant defense system and thereby reduced oxidative damage. These findings demonstrated that FA treatment could serve as an effective approach to retard the browning of fresh-cut taros and provided a basis for the feasible application of FA in the preservation of fresh-cut foods.

Evolution of fungal community associated with ready-to-eat pineapple during storage under different temperature conditions

The international market of fresh-cut products has witnessed dramatic growth in recent years, stimulated by consumer's demand for healthy, nutritious and convenient foods. One of the main challenging issues for the quality and safety of these products is the potential microbial spoilage that can significantly reduce their shelf-life. The complete identification of fresh-cut product microbiota together with the evaluation of environmental factors impact on microbial composition is of primary importance. We therefore assessed the fungal communities associated with the spoilage of ready-to-eat (RTE) pineapple using a metagenetic amplicon sequencing approach, based on the ITS2 region. Our results revealed a significant variability on fungal species composition between the different batches of RTE pineapple. The initial microbiota composition was the main influencing factor and determined the progress of spoilage. Temperature and storage time were the secondary factors influencing spoilage and their impact was depending on the initial prevalent fungal species, which showed different responses to the various modifications. Our results strongly suggest that further large-scale sampling of RTE pineapple production should be conducted in order to assess the full biodiversity range of fungal community involved in the spoilage process and for unravelling the impact of important environmental factors shaping the initial microbiota.