Recent developments on Opuntia spp., their bioactive composition, nutritional values, and health effects

Usefulness of Opuntia spp. on the Management of Obesity and Its Metabolic Co-Morbidities

The plants of the Opuntia genus mainly grow in arid and semi-arid climates. Although the highest variety of wild species is found in Mexico, Opuntia spp. is widely distributed throughout the world. Extracts of these cacti have been described as important sources of bioactive substances that can have beneficial properties for the prevention and treatment of certain metabolic disorders. The objective of this review is to summarise the presently available knowledge regarding Opuntia ficus-indica (nopal or prickly pear), and some other species (O. streptacantha and O. robusta) on obesity and several metabolic complications. Current data show that Opuntia ficus-indica products used in preclinical studies have a significant capacity to prevent, at least partially, obesity and certain derived co-morbidities. On this subject, the potential beneficial effects of Opuntia are related to a reduction in oxidative stress and inflammation markers. Nevertheless, clinical studies have evidenced that the effects are highly contingent upon the experimental design. Moreover, the bioactive compound composition of nopal extracts has not been reported. As a result, there is a lack of information to elucidate the mechanisms of action responsible for the observed effects. Accordingly, further studies are needed to demonstrate whether Opuntia products can represent an effective tool to prevent and/or manage body weight and some metabolic disorders.

Modulatory effects of dietary prickly pear (Opuntia ficus-indica) peel on high salinity tolerance, growth rate, immunity and antioxidant capacity of Nile tilapia (Oreochromis niloticus)

This study evaluated the effects of prickly pear (Opuntia ficus-indica) peel (PPP) on salinity tolerance, growth, feed utilization, digestive enzymes, antioxidant capacity, and immunity of Nile tilapia (Oreochromis niloticus). PPP was incorporated into four iso-nitrogenous (280 g kg-1 protein) and iso-energetic (18.62 MJ kg-1) diets at 0 (PPP0), 1 (PPP1), 2 (PPP2), and 4 (PPP4) g kg-1. Fish (9.69 ± 0.2 g) (mean ± SD) were fed the diets for 75 days. Following the feeding experiment, fish were exposed to a salinity challenge (25‰) for 24 h. Fish survival was not affected by the dietary PPP inclusion either before or after the salinity challenge. Fish fed the PPP-supplemented diets showed lower aspartate aminotransferase, alanine aminotransferase, cortisol, and glucose levels compared to PPP0, with the lowest values being observed in PPP1. Fish fed dietary PPP had higher growth rates and feed utilization than PPP0. Quadratic regression analysis revealed that the best weight gain was obtained at 2.13 g PPP kg-1 diet. The highest activities of protease and lipase enzymes were recorded in PPP1, while the best value of amylase was recorded in PPP2, and all PPP values were higher than PPP0. Similarly, PPP1 showed higher activities of lysozyme, alternative complement, phagocytic cells, respiratory burst, superoxide dismutase, glutathione peroxidase and catalase, and lower activity of malondialdehyde than in PPP0. Further increases in PPP levels above 2 g kg-1 diet led to significant retardation in the immune and antioxidant parameters. Thus, the inclusion of PPP at about 1 to or 2 g kg-1 diet can improve stress tolerance, immunity, and antioxidant capacity in Nile tilapia.

Tissue succulence in plants: Carrying water for climate change

Tissue succulence in plants involves the storage of water in one or more organs or tissues to assist in maintaining water potentials on daily or seasonal time scales. This drought-avoidance or drought-resistance strategy allows plants to occupy diverse environments including arid regions, regions with rocky soils, epiphytic habitats, and saline soils. Climate-resilient strategies are of increasing interest in the context of the global climate crisis, which is leading to hotter and drier conditions in many regions throughout the globe. Here, we describe a short history of succulent plants, the basic concepts of tissue succulence, the anatomical diversity of succulent morphologies and associated adaptive traits, the evolutionary, phylogenetic, and biogeographical diversity of succulent plants, extinction risks to succulents due to poaching from their natural environments, and the myriad uses and applications of economically important succulent species and the products derived from them. Lastly, we discuss current prospects for engineering tissue succulence to improve salinity and drought tolerance in crops.

Increased Zygote-Derived Plantlet Formation through In Vitro Rescue of Immature Embryos of Highly Apomictic Opuntia ficus-indica (Cactaceae)

O. ficus-indica (prickly pear cactus) is an important forage and food source in arid and semiarid ecosystems and is the most important cactus species in cultivation globally. The high degree of apomixis in the species is a hindrance in plant breeding programs where genetic segregation is sought for the selection of superior genotypes. To understand if in ovulo embryo rescue could increase the proportion of zygotic seedlings, we compared the mature seed-derived seedlings with those regenerated from in vitro embryo rescue at 20, 25, 30, 35, and 40 post-anthesis days (PADs) in four Italian cultivars. The seedlings were classified as apomictic or zygotic based on molecular marker analysis using inter-sequence single repeat (ISSR) primers. Multiple embryos were recovered from all the cultured immature ovules, and plantlets were regenerated and acclimatized to the field post hardening, with success rates ranging from 62% ('Senza spine') to 83% ('Gialla'). The level of polyembryony differed among cultivars and recovery dates, with the highest being 'Rossa', producing 4.8 embryos/ovule at 35 PADs, and 'Gialla', the lowest, with 2.7 at 40 PADs. The maximum number of embryos observed within a single ovule was 14 in 'Trunzara bianca'. ISSR analysis revealed that ovule culture at 35 PADs produced the highest percentage of zygotic seedlings in all the cultivars, from 51% ('Rossa') to 98% ('Gialla'), with a high genotype effect as well. Mature seeds produced much fewer seedlings per seed, ranging from 1.2 in 'Trunzara bianca' to 2.0 in 'Rossa' and a lower percentage of zygotic seedlings (from 14% in 'Rossa' to 63% in 'Gialla'). Our research opens a pathway to increase the availability of zygotic seedlings in O. ficus-indica breeding programs through in ovulo embryo culture.

New Functional Foods with Cactus Components: Sustainable Perspectives and Future Trends

The growing interest in a healthy lifestyle has contributed to disseminating perspectives on more sustainable natural resource management. This review describes promising aspects of using cacti in the food industry, addressing sustainable, nutritional, and functional aspects of the plant's production. Our study provides an overview of the potential of cacti for the food industry to encourage the sustainable cultivation of underutilized cactus species and their commercial exploitation. The commercial production of cacti has advantages over other agricultural practices by mitigating damage to ecosystems and encouraging migration to sustainable agriculture. The application of cactus ingredients in food development has been broad, whether in producing breads, jellies, gums, dyes, probiotics, and postbiotic and paraprobiotic foods. However, in the field of probiotic foods, future research should focus on technologies applied in processing and researching interactions between probiotics and raw materials to determine the functionality and bioactivity of products.

The Influence of the Addition of Hemp Press Cake Flour on the Properties of Bovine and Ovine Yoghurts

Hemp press cake flour (HPCF) is a by-product of hemp oil production rich in proteins, carbohydrates, minerals, vitamins, oleochemicals, and phytochemicals. The purpose of this study was to investigate how the addition of HPCF to bovine and ovine plain yoghurts at concentrations of 0%, 2%, 4%, 6%, 8%, and 10% could change the physicochemical, microbiological, and sensory properties of the yoghurts, focusing on the improvement of quality and antioxidant activity, and the issue of food by-products and their utilisation. The results showed that the addition of HPCF to yoghurts significantly affected their properties, including an increase in pH and decrease in titratable acidity, change in colour to darker, reddish or yellowish hue, and a rise in total polyphenols and antioxidant activity during storage. Yoghurts fortified with 4% and 6% HPCF exhibited the best sensory properties, thus maintaining viable starter counts in the yoghurts during the study period. There were no statistically significant differences between the control yoghurts and the samples with 4% added HPCF in terms of overall sensory score while maintaining viable starter counts during the seven-day storage. These results suggest that the addition of HPCF to yoghurts can improve product quality and create functional products and may have potential in sustainable food waste management.