Classification of different pineapple varieties grown in Malaysia based on volatile fingerprinting and sensory analysis

Innovative approaches for amino acid production via consolidated bioprocessing of agricultural biomass

Agricultural plantations in Indonesia and Malaysia yield substantial waste, necessitating proper disposal to address environmental concerns. Yet, these wastes, rich in starch and lignocellulosic content, offer an opportunity for value-added product development, particularly amino acid production. Traditional methods often rely on costly commercial enzymes to convert biomass into fermentable sugars for amino acid production. An alternative, consolidated bioprocessing, enables the direct conversion of agricultural biomass into amino acids using selected microorganisms. This review provides a comprehensive assessment of the potential of agricultural biomass in Indonesia and Malaysia for amino acid production through consolidated bioprocessing. It explores suitable microorganisms and presents a case study on using Bacillus subtilis ATCC 6051 to produce 9.56 mg/mL of amino acids directly from pineapple plant stems. These findings contribute to the advancement of sustainable amino acid production methods using agricultural biomass especially in Indonesia and Malaysia through consolidated bioprocessing, reducing waste and enhancing environmental sustainability.

Enhancing Odor Analysis with Gas Chromatography-Olfactometry (GC-O): Recent Breakthroughs and Challenges

Gas chromatography-olfactometry (GC-O) has made significant advancements in recent years, with breakthroughs in its applications and the identification of its limitations. This technology is widely used for analyzing complex odor patterns. The review begins by explaining the principles of GC-O, including sample preparation, separation methods, and olfactory evaluation techniques. It then explores the diverse range of applications where GC-O has found success, such as food and beverage industries, environmental monitoring, perfume and aroma development, and forensic analysis. One of the major breakthroughs in GC-O analysis is the improvement in separation power and resolution of odorants. Techniques like rapid GC, comprehensive two-dimensional GC, and multidimensional GC have enhanced the identification and quantification of odor-active chemicals. However, GC-O also has limitations. These include the challenges in detecting and quantifying trace odorants, dealing with matrix effects, and ensuring the repeatability and consistency of results across laboratories. The review examines these limitations closely and discusses potential solutions and future directions for improvement in GC-O analysis. Overall, this review presents a comprehensive overview of the recent advances in GC-O, covering breakthroughs, applications, and limitations. It aims to promote the wider usage of GC-O analysis in odor analysis and related industries. Researchers, practitioners, and anyone interested in leveraging the capabilities of GC-O in analyzing complex odor patterns will find this review a valuable resource. The article highlights the potential of GC-O and encourages further research and development in the field.

Comparison of Phenolic and Volatile Compounds in MD2 Pineapple Peel and Core

The peel and core discarded from the processing of MD2 pineapple have the potential to be valorized. This study evaluated the functional and volatile compounds in the extracts of MD pineapple peel and core (MD2-PPC). The total soluble solids, pH, titratable acidity, sweetness index, and astringency index were 9.34 °Brix, 4.00, 0.74%, 12.84, and 0.08, respectively, for the peel and 12.00 °Brix, 3.96, 0.32%, 37.66, and 0.03, respectively, for the core. The fat and protein contents of the peel and core were found to be significantly different (p < 0.05). The total phenolic (TPC) and flavonoid contents (TFC) were significantly higher in the peel. The peel also showed better antioxidant activity, with a half-maximal inhibitory concentration (IC₅₀) of 0.63 mg/mL for DPPH free radical activity compared with the core. The TPC of different phenolic fractions from peel extract was highest in the glycosylated fraction, followed by the esterified, insoluble-bound, and free phenolic fractions. GC-MS analysis identified 38 compounds in the peel and 23 in the core. The primary volatile compounds were 2-furan carboxaldehyde, 5-(hydroxymethyl), and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP). The identification of phenolics and volatile compounds provides important insights into the valorization of (MD2-PPC) waste.

Review of the Aroma Chemistry of Pineapple (Ananas comosus)

Pineapple (Ananas comosus), one of the most flavorful and popular tropical fruits consumed worldwide, is known to contain many volatile organic compounds (VOCs) at varying concentrations. Much attention has been paid to understand which VOC plays a significant role in the sensory aroma notes of the fruit. Though, nearly 480 VOCs have been identified to date using different analytical techniques, only 40 compounds are reported to contribute to the unique flavor of pineapple. A consolidated database of the reported VOCs and key aroma compounds of pineapple is currently not available. This review discusses the available published data regarding the analytical methodologies, volatile profile of different varieties of pineapple at different maturities, and their characteristic aroma compounds. The output of this review is a subset of key pineapple aroma volatiles that can be targeted in analytical method development for utilization in varietal improvement or other research of pineapple.

Pineapple waste in animal feed: A review of nutritional potential, impact and prospects

Pineapple is a commodity and economic fruit with a high market potential worldwide. Almost 60 % of the fresh pineapple, such as peels, pulp, crowns and leaves, are agricultural waste. It is noteworthy that the waste has a high concentration of crude fibre, proteins, ascorbic acid, sugars and moisture content. The pineapple waste utilisation in animal feed has recently drawn the attention of many investigators to enhance growth performance and concomitantly reduce environmental pollution. Its inclusion in animal feed varies according to the livestock, such as feed block, pelleted or directly used as a roughage source for ruminants. The pineapple waste is also fermented to enrich the nutrient content of poultry feed. To date, the inclusion of pineapple waste in animal feed is optimistic only not for livestock but also for farmed fish. Indeed, it is an ideal strategy to improve the feed supply to the farm. This paper aims to overview the source, nutritional composition, and application of pineapple waste in animal feed. The recent findings on its effect on animal growth performance, nutrition and disease control are discussed comprehensively and summarised. The review also covers its benefits, potential impacts on sustainable farming and future perspectives.

Heterologous Expression and Catalytic Properties of Codon-Optimized Small-Sized Bromelain from MD2 Pineapple

Bromelain is a unique enzyme-based bioactive complex containing a mixture of cysteine proteases specifically found in the stems and fruits of pineapple (Ananas comosus) with a wide range of applications. MD2 pineapple harbors a gene encoding a small bromelain cysteine protease with the size of about 19 kDa, which might possess unique properties compared to the other cysteine protease bromelain. This study aims to determine the expressibility and catalytic properties of small-sized (19 kDa) bromelain from MD2 pineapple (MD2-SBro). Accordingly, the gene encoding MD2-SBro was firstly optimized in its codon profile, synthesized, and inserted into the pGS-21a vector. The insolubly expressed MD2-SBro was then resolubilized and refolded using urea treatment, followed by purification by glutathione S-transferase (GST) affinity chromatography, yielding 14 mg of pure MD2-SBro from 1 L of culture. The specific activity and catalytic efficiency (k_cat/K_m) of MD2-SBro were 3.56 ± 0.08 U mg⁻¹ and 4.75 ± 0.23 × 10⁻³ µM⁻¹ s⁻¹, respectively, where optimally active at 50 °C and pH 8.0, and modulated by divalent ions. The MD2-SBro also exhibited the ability to scavenge the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) with an IC₅₀ of 0.022 mg mL⁻¹. Altogether, this study provides the production feasibility of active and functional MD2-Bro as a bioactive compound.

Characterisation of Pineapple Cultivars under Different Storage Conditions Using Infrared Thermal Imaging Coupled with Machine Learning Algorithms

The non-invasive ability of infrared thermal imaging has gained interest in various food classification and recognition tasks. In this work, infrared thermal imaging was used to distinguish different pineapple cultivars, i.e., MD2, Morris, and Josapine, which were subjected to different storage temperatures, i.e., 5, 10, and 25 °C and a relative humidity of 85% to 90%. A total of 14 features from the thermal images were obtained to determine the variation in terms of image parameters among the different pineapple cultivars. Principal component analysis was applied for feature reduction in order to prevent any effect of significant difference between the selected features. Several types of machine learning algorithms were compared, including linear discriminant analysis, quadratic discriminant analysis, support vector machine, k-nearest neighbour, decision tree, and naïve Bayes, to obtain the best performance for the classification of pineapple cultivars. The results showed that support vector machine achieved the best performance from the combination of optimal image parameters with the highest classification rate of 100%. The ability of infrared thermal imaging coupled with machine learning approaches can be potentially used to distinguish pineapple cultivars, which could enhance the grading and sorting processes of the fruit.

Effect of feeding pineapple waste on growth performance, texture quality and flesh colour of nile tilapia (Oreochromis niloticus) fingerlings

The study aims to evaluate the effects of pineapples waste on the growth, texture quality and flesh colour of Nile tilapia (Oreochromis niloticus) fingerlings. Fingerlings were fed with four different levels of pineapple waste diets throughout 56 days, which contain a control group (Diet 1) and experimental diets that formulated with 10% (Diet 2), 20% (Diet 3) and 30% (Diet 4) of pineapple waste. The experimental diet was formulated with rice bran, fish meal, soybean meal, vitamin and mineral premix, vegetable oil and binder to attain 32% dietary protein. The results revealed that the formulated fish diet with pineapple waste given the optimum weight gain, weight gain percentage, specific growth rate than the control group, where Diet 4 has shown the highest value (p < 0.05). There were no effects of the pineapple waste diet on the texture quality of the fillet, while only red chromaticity (a*) showed a significant difference (p < 0.05). In conclusion, the addition of pineapple waste can improve the growth rate of Nile tilapia, and the supplementation level of the pineapple waste in the diet was 30% of the total feed formulation.

Influence of post-harvest physiology on sensory perception, physical properties, and chemical compositions of Moris pineapples (Ananas comosus L.)

This study was conducted to evaluate consumer profiling of pineapple at five maturity stages using check-all-that-apply (CATA) method and to determine the influence of post-harvest physiological changes on the physical and chemical properties of the pineapple. Nineteen CATA terms describing sensory attributes of pineapples at five maturity stages were generated. Seventy-five consumers were involved in describing the changes in the organoleptic properties of pineapple using CATA questions. The relationship between physicochemical properties and sensory description of pineapples was analyzed using correspondence analysis (CA). The total variance of 97.7% and 92.2% obtained in the CA plot of the physical and chemical properties with the consumer profiling data suggests that consumers have effectively described the pineapple harvested at five maturity stages. Changes in physical and chemical compositions in pineapple upon maturation result in the development of pineapple's desirable organoleptic characteristics, characterized as fresh, attractive, and bright yellowish, with a soft, fibrous, and juicy texture, a sweet odor and pineapple aroma as well as sweet taste. Index 3 pineapple has been described as pale, hard, and crunchy in texture at the early stage of maturity and has a sour taste. The characteristic was transformed to bright yellow, soft, fibrous, and juicy texture after maturation, (25% ripeness onwards), as well as the production of sweet taste and aroma of pineapple. Instrument analysis of yellowness (b value) and carotenoid has strongly influenced the sensory attributes of brightness, freshness, and attractiveness of the pineapple. Changes in total soluble solids (TSS) and a ratio of TSS to total acids (TA) contributes to the development of aromatic compound which increases the appealing quality of the pineapple. Pineapple sensory characteristics, physical properties, and chemical compositions were significantly affected by post-harvest physiology. PRACTICAL APPLICATION: Sensory and instrumental methods were used to construct the properties of pineapple at different stages of post-harvest physiology. This article demonstrates that the Check-all-that-apply (CATA) analysis provides adequate sensory profiling information based on customer perceptions in relation to instrumental details, and it can be extended to other pineapple varieties and citrus fruits.

Characterization of the key aroma compounds in three types of bagels by means of the sensomics approach

Background

To evaluate the impact of cold fermentation time on bagel rolls, the key aroma-active compounds in the volatile fractions obtained from three different bagel rolls through solvent assisted flavor evaporation (SAFE) were sequentially characterized by an aroma extract dilution analysis (AEDA), quantified by stable isotope dilution and analyzed by odor activity values (OAVs) respectively.

Results

Findings revealed 40 aroma-active compounds with flavor dilution (FD) factor ranges of 2–1024. Of these, 22 compounds (FD ≥ 16) were quantified by stable isotope dilution assays (SIDA). Subsequent analysis of the 22 compounds by odor activity values (OAVs) revealed 14 compounds with OAVs ≥ 1 and the highest concentrations were obtained for 2,3-butanedione, 2-phenylethanol, 3-methylbutanal and acetoin respectively. Two recombination models of the bagels (i.e. 24 h and 48 h bagels) showed similarity to the corresponding bagels. Omission tests confirmed that 2,3-butanedione (buttery), acetoin (buttery), 2-acetyl-1-pyrroline (roasty), 5-methyl-2-furanmethanol (bread-like), (Z)-4-heptenal (biscuit-like) and 4-hydroxy-2,5-dimethyl-3(2H)-furanone, were the key aroma compounds. Additionally, acetic acid, butanoic acid, 2-phenylethanol (honey-like), 3-methylbutanoic acid, 2/3-methylbutanal, vanillin, 3-methylbutanol, methional were also important odorants of the bagel.

Conclusion

Whilst the long, cold fermented bagels exhibited roasty, malty, buttery, baked potato-like, smoky and biscuit-like notes, the control bagels produced similar but less intense odor notes.