Development of fiber-enriched muffins using pomegranate peel powder and its effect on physico-chemical properties and shelf life of the muffins

BACKGROUND

Pomegranate peel is a by-product from the pomegranate processing industries and is a rich source of dietary fibers and bioactive compounds. It has good antioxidant and antimicrobial properties. In the present study, the effects of substitution of refined wheat flour with pomegranate peel powder (PPP) at a rate of 2%, 4%, 6%, 8% and 10% on the physico-chemical and sensorial properties as well as on the oxidative and microbial stability of muffins were investigated.

RESULTS

A significant reduction in specific volume (1.99 to 1.57 cm3  g-1 ), weight loss (11.73 to 10.14 g 100 g-1 ) and an increase in crumb hardness (633.06 to 2311.5 g) of muffins were observed on addition of PPP. Moreover, the nutritional value was improved by a significant increase in the fiber content (4.39 to 10.66%), total phenols (0.443 to 48.53 mg GAE 100 g-1 ), antioxidant activity (75.94% to 99.36%), calcium (200.33 to 294.33 mg 100 g-1 ), potassium (227.33 to 425.33 mg 100 g-1 ) and magnesium (96.33 to 288.33 mg 100 g-1 ). The pasting and rheological properties of muffin batter showed a significant decrease in the final and peak viscosity, as well as increase in storage, loss and complex modulus. The muffin samples were organoleptically acceptable up to a level of 8% PPP. Free fatty acid content, peroxide value and microbial count of the muffin with 8% PPP were significantly lower compared to the control sample and more oxidatively and microbially stable for a storage period of 21 and 28 days at ambient and refrigerated temperatures, respectively.

CONCLUSION

The present study provides the opportunity to use PPP as functional ingredients and natural preservative in the preparation of muffins. © 2023 Society of Chemical Industry.

Morphological, Biochemical, and Molecular Diversity of an Indian Ex Situ Collection of Pomegranate (Punica granatum L.)

Pomegranate (Punica granatum, L.) is a fruit tree that is increasingly popular worldwide due to the health-related properties of the fruit juice. While several studies highlighted the rich phytochemical diversity, few efforts have been devoted to an integrative understanding of the level of diversity of this species. This study investigated the diversity of 40 pomegranate accessions in an Indian ex situ collection by using twenty-nine morphological traits, six biochemical parameters, and twenty-nine Simple Sequence Repeats (SSR) markers. Among the evaluated traits, fruit volume (23.34% CV), fruit weight (21.12% CV), and fruit color (*a) (22.69 % CV) largely contributed to the morphological classification. Based on Mahalanobis D² distance and Tocher's clustering, the 40 pomegranate accessions were grouped into eight clusters, partly consistent with their origin. Specifically, cultivars introduced from foreign countries were present in distinct clusters. The SSR marker analysis generated 66 alleles. The observed heterozygosity values ranged from 0.05 to 0.63, with a mean value of 0.30. Maximum molecular genetic dissimilarity was observed between 'IC-318720' and 'Gul-e-Shah Red' (0.30). The neighbor-joining dendrogram separated wild accessions from cultivated varieties. The combination of morphological, biochemical, and molecular characterization allowed for comprehensively characterizing the pomegranate diversity and provided information on the relationships between the different aspects of the diversity. This work also suggests that the origin of the accessions is an important factor of discrimination and that the level of admixture between local and foreign material is currently limited.

Identification and validation of SSR markers for Xanthomonas axonopodis pv. punicae an incitant of bacterial blight of pomegranate

This study reports genome wide characterization and development of first set of microsatellite markers through in silico analysis of eight sequenced Xanthomonas axonopodis pv. punicae strains available in the public database. SSR survey resulted in identification of ~ 4638 perfect SSRs, with mean marker frequency 901 SSRs/Mb and densitiy of 11,006 bp/Mb aross the eight genomes. Frequency distribution graphs revealed hexa-nucleotide repeats were more prominent fowllowed by tri-, tetra-, di- and penta-nucleotides in the analysed genomes. We desinged 2927 SSR primers that are specific to the strain LMG 859 and ePCR confirmed on seven other Xap genomes. This resulted in identification of 542 informative SSRs that are producing single amplicons, from which 66 primers were successfully validated through wet lab experiments on eight Xap isolates of pomegranate. Furthermore, utility of these SSRs were demostrated by analysing molecular diversity among 22 Xap isolates using 20 Xap_SSR primers. SSRs revealed moderate genetic diversity among Xap isolates (61%) and grouped 11 isolates that are repersenting six different states into one cluster. This proved the earlier evidence of wider spread of ST3 type Xap acoss India using Multi locus Sequence Typing (MLST) technique. In summary, Xap_SSR will serve as powerful genomics tools that would helps in monitoring of population dynamics, taxonomy, epidomology and quarantine aspects in bacterial blight pathogen through development of microsatellite based Multilocus Variable number of Tandem repeat analysis (MLVA) in future.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03209-z.

Response of Nagpur mandarin (Citrus reticulata Blanco) to high density planting systems

High density planting system i.e. accommodating a higher number of plants than routine in a given area is an innovative agro-technology to increase yield and thereby early net returns. Due to conventional wide spacing plantation in Nagpur mandarin (Citrus reticulata Blanco), the land remains unutilized as the plant canopy gradually increases over the years. In the present study, Nagpur mandarin (Citrus reticulata Blanco) budded on Rangpur lime rootstock was evaluated under six different planting spacings. It was observed that the organic carbon (1.10–1.82%) and major nutrients viz. N (309–430 kg ha⁻¹), P (20–54 kg ha⁻¹) and K (291–810 kg ha⁻¹) increased vis-à-vis plant density and was highest under 2 × 2 m spacing. Plants were tallest at 2 × 2 m spacing with the higher PAR interception (88.2) and the lowest leaf area index (1.09). Fruit yield on area basis, under 2 × 2 m spacing was 26, 7.1, 4.6 times more as compared to conventional plantation during the first, second and third year, respectively. At fifth year of crop harvest, the highest B:C ratio (6.36) was recorded in 6 × 3 m followed by 4 × 2 m and 2 × 2 m.